Tuesday, February 8, 2011

KINGDOM PROTISTA

Kingdom Protista
          - artificial grouping of organisms coming from different evolutionary lineages

*Animal-like Protists
          - protozoans
          - heterotrophs
          - unicellular
          - no cell wall
          - aquatic: free-living
                           parasitic
          - motile: flagella
                         pseudopodia
                         cilia
Zooflagellates
          - flagella
          - fast swimmers
          - reproduce by binary fission
          - mostly free-living
     *Triconympha
          - lives in symbiosis with termites
          - helps termites breakdown cellulose
          - host to two parasitic prokaryotes (bacteria)
     *Trypanosomes
          - Trypanosoma gambiense
          - Trypanosoma rhodesiense
               - african sleeping sickness
               - flea or tsetse fly
Sarcodines
          - with pseudopodia
          - Amoeba proteus
               - looks like a shapeless mass of cytoplasm
               - creates a fingerlike projections called pseudopodia
               - uses diffusion as a way of exchanging gases to and out of the cell
               - osmosis - water
          - Entamoeba histolytica
               - causes amoebiasis
Foramineferans
          - live in marine waters
Actinopoda
          - radiolarians and heliozoans
     *Heliozoans
          - floaters
          - freshwaters
          - free-living
          - bottom-dwellers
     *Radiolarians
          - ocean drifters
          - part of planktons
          - filter feeder or predator
Ciliates
          - cilia
     *Paramecium
          - Paramecium and stentor
               - colonial
          - Epistylis
               - parasitic
               - Balantidium coli
               - diarrhea
Apicomplexans
          - immobile (lacks structures for motility)
          - sporozoans
          - parasitic
               - Plasmodium
                    - malaria
                    - mosquito bites
                    - Anopheles

*Fungus-like Protist
          - heterotrophs
          - decompose dead organic matter
          - body is composed of filaments
          - reproduce through spores
          - produce flagellated cells (difference with the true fungus)
          - cells contains centrioles
    
     GROUPS
Plasmodial Slime Molds
          - colorful
          - creeping on moist forest soil and dead leaves
          - move by pseudopodia
          - feed on microbes
          - has plasmodium
                - motile, large, brnaching structure
          - not multicellular
Water Molds
          - oomycetes
          - "egg-fungus"
          - with long, filamentous bodies
          - with several nuclei
          - cell wall is composed of cellulose
          - produce sporangia that release zoospores
          - aquatic saprophytes
          - seen on dead insects, salmon, immobile eggs
               - Saprolegnia
                    - grows as a fluffy white mass on the body of decaying fish
                    - body is thin and branched
                    - produces asexually
Down Mildews
          - aggresive plant pathogens
               - Phytophthora infestans
                    - potato late blight
                    - causes softening and rotting of plant parts

*Plant-like Protists
         - algae
         - have chloroplasts
         - autotrophs
         - single, colonial, or multicellular

Euglenoids
        - single-celled
        - not exclusive autotrophs
             - Euglena
                  - freshwater
                  - no cell wall
                  - with long flagellum
                  - its eyespot directs the cell towards sunlight
Dinoflagellates
          - with distinctive spinning movement
          -part of phytoplankton
          - reproduce by binary fission
          - population explosion - algal blooms
               - red tide
               - brown tide
     *Bioluminescence
               - ability to produce light
Diatoms
          - single celled or colonial
          - most abundant organism in phytoplankton
          - yellow or brown due to the pigments in its chloroplasts
          - float because of oil (produces during photosynthesis)
          - cell is made up of silica
          - diatomaceous earth
Seaweeds
          - multicellular
          - no cuticle
          - no true roots, stem and leaves
Brown Algae
          - kelps (largest seaweeds)
          - source of algin
Red Algae
          - mostly multicellular
          - mostly marine
          - no more than 1m
          - builder of coral reefs
          - source of agar and carrageenan
Green Algae
          - most similar to plants
          - with chlorophyll and starch

BACTERIA

*Aerobic Photoautotrophs
          - rely on sunlight as a source of energy and CO2 as a source of carbon
          - primary producers
     *Cyanobacteria
          -blue-green bacteria (blue-green algae)
          - with chlorophyll a + bluish pigment
          - like plants (photosynthesis)
          - supplied O2 to premedial Earth
     *Nitrogen Fixers
          - fixation of atmospheric nitrogen
          - develop heterocysts

*Anaerobic Photoautotrophs
          - lack the key light-trapping pigment of plants, chlorophyll a anb b
          - with bacteriochlorophylls
          - purple and green bacteria
          - rely on hydrogen sulfide or H2 gas instead of H2O
          - don't produce O2

*Chemoheterotrophs
     *disease-causing bacteria
          - pathogens
     *decomposers
          - produce enzymes that breakdown organic compounds
     *fermenters

*Commercially Important Bacteria
          - used to address environmental problems
     ex: pseudomonads

Saturday, February 5, 2011

ARCHAEA

Reproduction
     Asexual
          - binary fission
          - endospore
     Sexual
          - conjugation

Types

Methanogens
     - oxygen free habitats
     - produce methane gas
     - extract energy from hydrogen gas and carbon dioxide
     - in bogs, deep soil, mud bottoms of lakes
     - reminants expel CH4


Extreme Halophiles
     - extra high salt contents
     - with unique glycoproteins
     - accumulate K ions and keep out Na ions
     - generate energy by aerobic respiration
     - use bacteriorhodopsin to perform photosynthesis
     - carry carotenoids for UV protection

Extreme Thermoacidophile
     - hot and acidic water
     - sulfur-rich hot springs, hydrothermal vents (110 C)
     - obligate anaerobes
     - uses S instead of O2

PROKARYOTES II

Bacteria
     - membranes contain unbranched fatty acids
     - cell wall contains peptidoglycan
Gram +
     - thick layer of peptidoglycan
     - penicillin
Gram -
     - thin layer
     - streptomycin or tetracyline

Archaea
     - membranes have branched isoprene chains
     - for extreme conditions
     - cel wall contain no peptidoglycan

SIMILARITIES
     - cellular
     - DNA and RNA
     - manufacture their own enzymes
     - genetic material found in cytosol
     - no mitochondrion, ER, Golgi bodies, lysosomes
     - some produce capsule
     - offer protection against defense cells
     - pili - for attachment
          - hairlike structures

PROKARYOTES I

Prokaryotes
     - bacteria
     - archaea

     - cellular
     - DNA and RNA
     - ribosomes
     - don't host
     - well-coordinated system of enzymes

Size
     - small
     - Thiomargarita namibiensis
          - biggest prokaryote
          - "sulfur pearl of Namibia"

Shape and Arrangement of Cells

Cocci - spherical prokaryotes
Bacilli - rod-shaped prokaryotes
Spirilla - spiral

Infectious Particles

Viroids
     - naked, single stranded RNA
     - cadang-cadang, spindle tuber disease

Prions
     - protein particles
     - brain diseases
          - mad cow disease
          - Creutzfeldt Jacob disease
          - scrapie
          - kuru

VIRUS

Virus
          - particles smaller than cells
          - noncellular
          - specific
          - DNA or RNA
Martinus Beijerinck
         - first to use the term virus


STRUCTURE
     - capsid- protein surrounding the DNA or RNA
     - bacteriophages - virus infecting bacteria

DNA viruses
          - hepa B, smallpox, cowpox, herpes
RNA viruses
          - AIDS, mumps, common colds, leukemia, measles

Monday, December 13, 2010

TAXONOMY

Taxonomy
         - science of naming, classifying, and identifying organisms
         - systematics

Levels of Classification (taxa)

     1. Kingdom          4. Order      7. Species
     2. Phylum             5. Family
     3. Class                 6. Genus

Phylogeny
          - natural system of classification that is based on the evolutionary history or genealogy shared by a group of organisms.

Phylogenetic Trees
         - show how related organisms evolved from common ancestors
Method:
     Cladistics
           - involves identifying shared derived traits

Carolus Linnaeus
     - binomial nomenclature
genus
  • tells more about the organism
  • always capitalized
species
  • lower case
Genus and species form the scientific name.  It is either italicized or underlined.

Aristotle
          - father of animal classification
          - land, air, water
          - "species", belonging to the same kind

Artificial Systems
         - took into account only a few characteristics
         - Aristotle and Carolus Linnaeus

Tuesday, November 23, 2010

EVOLUTION

Early Concepts of Evolution

Aristotle: nature evolved gradually from the simple to the more complex and from imperfect to perfect

Lucretius: wrote an evolutionary explanation of the origin of plants and animals

Leonardo da Vinci: put forward the theory of catastrophism
                              explains that fossil found in rocks resulted from a succession of fires and flood
                              that destroyed all things some time in the prehistoric past

Theory of Uniformatarianism

James Hutton: concluded that the formation of sedimentary deposits was due to geological forces
                       of erosion, sedimentation, uplift, and disruption on that were working in the past
                       and one continuing to the present

John Playfair: further explained and supported Hutton's concept

Sir Charles Lyell: proved beyond reasonable doubt the idea of geologic evolution through
                          his book Principles of Geology

GENETICS

Mendel's Princples of Inheritance
  1. The F1 generation showed only dominant traits
  2. In the F2 generation, both the dominant and recessive traits reappeared
  3. In the F2 generation, there were 3x as many plants with the dominant traits than plants with recessive traits
LAW OF SEGREGATION
          - Mendel inferred that the two factors determining a trait segregates when the sex cells are formed
          - Each gamete (egg cell or pollen) is equally likely to contain either traits
phenotypes: trait of a plant (tall)
genotypes: the pair of alleles for that trait (TT or Tt)

LAW OF DOMINANCE

LAW OF INDEPENDENT ASSORTMENT
          - alleles of the gene pair for a particular pair of traits segregate independently of the alleles of gene pairs for the trait

MEIOSIS

MEIOSIS
          - type of cell division involving reproductive cells

Phases

Meiosis I
     stages:

Prophase I
  • two sister chromatids of each chromosome pair up with the chromatids of its homologue (synapsis)
  • makes up 90% of the entire process
  • forms a structure called tetrads
  • chromatids of homologous chromosomes exchange segments (crossing-over)
  • nucleoli and nuclear membrane start to disappear
Metaphase I
  • homologous chromosomes align at the middle of the cell
Anaphase I
  • movement of the chromosomes of each homologous pair toward the opposite poles of the cell
  • individual chromosome still consist of two sister chromatids
Telophase I and Cytokinesis
  • chromosomes are on each side of the pole
  • chromosome still consist of two sister chromatids
  • nucleoli and nuclear membrane reappear

Meiosis II
     stages:

Prophase II
  • starts with haploid cells
  • nuclear envelope starts to breakdown
Metaphase II
  • chromosomes line up along the cell equator
Anaphase II
  • chromosomes are pulled toward the opposite poles of the cell
Telophase II
  • chromosomes finish their migration to poles
  • nuclear membrane forms again and nucleolus reappear
Cytokinesis
  • four new daughter cells are produced, each with a haploid number of chromosomes

Saturday, November 13, 2010

MITOSIS

VOCABULARY :
  • Cell Division - process by which cell reproduce
  • Chromosomes - cell parts that determine what traits a living thing will have
  • Chromatid - one strand of DNA, after replication, a chromosome is made up of two identical chromatids
  • Daughter Cells - new cells produced by cell division
  • Cytokinesis - a division of the cytoplasm of one parent cell into two daughter cells
Interphase
          - DNA has replicated but has not formed the condensed structure of chromosome. They remain as loosely coiled chromatin. The nuclear membrane is still intact to protect the DNA molecules from undergoing mutation.
   G1
   S - synthesis (DNA)
   G2

Early Prophase
          - the nuclear membrane breaks down
          - chromosomes shorten and thicken
          -centrioles are forming

Late Prophase
          - centriole pairs move apart
          - nuclear envelope starts to break up

Metaphase (midddle)
          - the chromosomes are lined up along the cell's equator
          - are attached to the mitotic spindle

Anaphase (away)
          - the newly formed chromosomes are pulled toward opposite poles of the cell

Telophase
         - the chromosomes have finished their migration to the poles
         - the plasma  membrane of the cell pinches down along the equator
         - the nuclear membrane forms again and the nucleolus reappears

Cytokinesis
         - after mitosis, two diploid daughter cells have formed
  

Friday, October 1, 2010

Fermantation

FERMENTATION
  • is the breakdown of pyruvic acid without the use of oxygen
  • no ATP produced
  • alcoholic and lactic acid

Alcoholic Fermentation
          - occurs in plant cells and some one-celled organisms (yeasts)
pyruvic acid + NADH + H ----------> CH3CH2OH + CO2 + NAD (returns to glycolysis)


Lactic Acid Fermentation
          - takes place when there is a short supply of oxygen in cells
pyruvic acid + NADH + H ----------> Lactic Acid + NAD (reused in glycolysis)


AEROBIC RESPIRATION
  • large amount of energy is released from a glucose molecule
  • takes place in the matrix and cristae (mitochondrion)
  • occurs as a series of chemical reaction in which oxygen is used to convert the chemical energy stored in a organic food molecule to ATP and reduced H2 acceptor
  • has 3 stages :
                                 - conversion of pyruvic acid to acetyl-CoA
                                 - Krebs cycle or Citric Acid Cycle
                                 - electron transport chain

1. Conversion of Acetyl-CoA
          - happens instead of lactic acid fermentation when you have enough oxygen
P.A. + CoA + NAD ----------> Acetyl-CoA + CO2 + NADH  + H
          1 glucose molecule = 2 molecules of Acetyl-CoA
          1 glucose molecule = 2 Pyruvic acid
                 1pyruvic acid  = 1 Acetyl-CoA


2. Krebs Cycle
          - From Sir Hans Adolf Krebs
          - The central biochemical pathway of aerobic respiration
          - Also called citric acid  cycle
          - Occurs in the inner matrix of the mitochondrion
          - Consists of :
                    - Dehydration (removal of water)
                    - Hydration (addition of water)
                    - Decarboxylation (removal of carbon dioxide)
                    - Dehydrogenation (removal of hydrogen)


3. Electron Transport Chain
         - oxidative phosphorylation
         - The breakdown of glucose is complete
         - 4 new ATP molecules are made
         - involves cytochromes (class of proteins that fuctions as electron transporter)
         - water is a by-product

Sunday, August 29, 2010

CELL RESPIRATION

GLYCOSIS
          - the conversion of glucose into a reactive compound, pyruvic acid
          - occurs in the cytosol
          - has 4 major stages

                                                           GLUCOSE
                                                                   | phosphorylated
                                                                   |
                                                       Glucose-6-phosphate
                                                                   |
                                                                   |
                                                        Fructose-6-phosphate
                                                                   |
                                                                   |
                                                     Fructose1, 6 Diphosphate
                                                                 /  \
                                                                /    \
                                                               /      \
                                                              /        \
                                                       PGAL     PGAL
                                                        (3-C)      (3-C)
                                                            |              |
                                                         +P            +P
                                                           |               |
                                             Pyruvic Acid     Pyruvic Acid

PHOTOSYNTHESIS II

PHOTOSYNTHESIS

Two Raw Materials
          - Carbon Dioxide - stomata
          - Water - xylem vessels

                     CO2 + H2O + light ------------> C6H12O6 + H2

Two Processes
  • Light Dependent or Photolysis
  • Light Independent or Dark Reaction

LIGHT DEPENDENT
          - also called photolysis
          - occurs in the thylakoids
          - involves: Photosystem I
                          Photosystem II

Photosystem I
          - reaction center is 700
          - far-red region
          - more in chlorophyll a

Photosystem II
          - reaction center is 680
          - red region
          - in chlorophyll a and chlorophyll b

LIGHT ENERGY --------> chlorophyll a
                                (electrons excited)(P680)
                                                   |
                                                   |
                                      energized chlorophyll
                                                   / \
                                                  /   \
                                  splits water    adds P1
                                         / \                |
                                        /   \               |
                                     2H  O2     ADP(energy carrier)
                                       |                    |
                                       |                    |
                       NADP(H acceptor)    ATP
                                       |                    |
                                       |                    |
                                 NADPH          energy   
                                         \                   /
                                           \               /
                                    DARK REACTIONS

LIGHT INDEPENDENT
          - dark reactions
          - Calvin-Benson reaction
          - carbon fixation
          - occurs in the stroma

                                                      CO2
                                                          |
                                                          |
                                                   RuDP(CO2 acceptor)
                                                          |
                                                          |
                                           6-C sugar (very unstable)
                                                          | splits
                                                          |
                                 2 mols. of PGA (3 carbon compound) 
                                                          | combine
                                                          |    with
                                 2H from NADPH (from Light Reaction)
                                                        / \
                                                       /   \
                                                      /     \
                                             PGAL    H20 released as by products
                                                / \
                                               /   \
                                      RuDP    Glucose

External Factors that Affect Photosynthesis

1. light
2. Carbon Dioxide
3. temperature
4. water supply
5. minerals

Internal Factors

1. leaf structures
2. amount of photosynthetic products
3. enzymes    

Friday, August 20, 2010

PHOTOSYNTHESIS

PHOTOSYNTHESIS
          - a complex process that uses light energy to convert carbon dioxide and water into carbohydrates.


Discoveries on Photosynthesis


Jan van Helmont
          - Flemish botanist
          - first who studied photosynthesis
          - on 1630 he concluded that plants make their own organic materials and donot get these from the
             soil. 


Joseph Priestly
          - in 1772, he showed that a sprig of mint would restore air that had been injuredby a burning
            candle.
          - the results showed that oxygen gas, which is used up in burning, is released by plants.


Jan Ingenhouz         
          - supported the findings of Priestly
          - in 1779, he added that this air (oxygen) could only be restored by plants with sunlight.


Nicholas de Saussure
          - in1804, he made an experiment and its results showed that the increase in the dry weight of the plant
           was greater than the weight of the carbon dixide removed from the air.
          - concluded that aside from carbon dioxide, the other substance that contributed to the increase in the
           weight of the plant was water.


C. B. van Niel
          - in the 1930s, he was able to proved that light splits water, producing oxygen.


General Outline of Photosynthesis
carbon dioxide + water + light energy ----> organic material + oxygen + water


2 CLASSIFICATIONS


Heterotrophs
          - also called as "other-feeders"
          - cannot synthesize their own food and depend on autotrophs


Autotrophs
          - also called as "self-feeders"
          - synthesize their own food
          - has 2 main types:
               : photoautotrophs - include green plants and purple bacteria
               : chemoautotrophs - includes bacteria

 OXIDATION-REDUCTION PROCESS or REDOX REACTIONS
                     - involve the stable transfer of electrons between atoms.
It is said to be:

     Reduced - when an atom gains one or more electrons
     Oxidized - when it loses one or more electrons

Sunday, August 15, 2010

CELLULAR TRANSPORT

Cellular Transport

2 Kinds:

ACTIVE TRANSPORT
          - requires energy
Examples:
     Sodium-Potassium pump
     Bulk Transport

Bulk Transport

Endocytosis
     - engulfs
     - 3 kinds:

Phagocytosis
     - solid
Pinocytosis
     - liquid
Reverse Mediated Endocytosis
     - specific molecules

Exocytosis
     - reverse


PASSIVE TRANSPORT
          - does not requires energy
          - 2 kinds:

Diffusion
     - movement of molecules from an area of high concentration to an area of low concentration

Factors Affecting the Rate of Diffusion

1. Size of the diffusing molecule
2. Molecular weight of the diffusing substance
3. Structure and composition of cell
4. Concentration gradient
5. Temperature
6. Other external factors

Osmosis
     - the diffusion of water through a semipermeable membrane

hypotonic - the cell bursts
hypertonic - the cell shrinks
isotonic - nothing happens to the cell  

PROKARYOTIC CELLS and EUKARYOTIC CELLS

Prokaryotic Cells

          - Greek, pro 'before' and karyon 'kernel'
          - unicellular organisms
          - lack nucleus and other membrane-bounded structures
          - bacteria and blue-green algae
          - DNA is coiled into a nucleus-like region(nucleoid)


Eukaryotic Cells

          - Greek, eu 'true' and karyon 'kernel'
          - plants, animals, protists, fungi
          - multicellular organisms
          - well-defined nucleus
          - DNA is bounded within a nucleus
          - with membrane-bounded organelles
          - with cytoskeleton

THREE BASIC PARTS of a EUKARYOTIC CELL

1. Plasma Membrane or Cell Membrane
2. Cytoplasm
3. Nucleus

CELLULAR STRUCTURES and FUNCTIONS

> The Cell Membrane

          - a thin layer of lipid and protein molecules held by noncovalent bonds
          - separates the cell contents from the surrounding medium
          - ranges from 5-10 nanometers
          - controls the entrance and release of substances in the cell
          - mainly composed of phospholipid molecules

PHOSPHOLIPID MOLECULE
          - composed of glycerol, two fatty acids, and one phosphate group
Polar or Amphipatic
          - 2 ends have different properties in water
  • head - hydrophilic
  • tail - hydrophobic
> The Nucleus

          - the control centre of the eukaryotic cell
          - surrounded by nuclear envelope (double layer)
          - contains the DNA
          - 2 main functions
               - directs chemical reactions in cells
               - acts as storage of genetic information and transfers such information

The Cytoplasm

         - includes everything between the cell membrane and the nucleus
         - 2 main parts
               - Cytosol
                    - viscous colloidal substance of the cytoplasm
                    - where organelles are suspended
                    - site of major biological processes
               - Organelles

THE ORGANELLES

Mitochondrion
  • rod-shaped
  • carries out process of cellular respiration
  • "power-centre of the cell"
  • has two compartments
           : Intermembrane Space
                 - inner and outer membranes
                 - highly folded (cristae)
           : Matrix

Endoplasmic Reticulum
  • extensive network of membranes
  • connects the nuclear envelope to the cell membrane
  • 2 kinds :
      R.E.R
  • has ribosomes attached on its surface
  • makes more membranes
  • transport proteins within a cell
      S.E.R.
  • lacks ribosomes
  • synthesizes lipids (fatty acids, phosholipids and steroids)
Ribosomes
  • the protein factories of the cell
  • attached to the E.R. (R.E.R.)
Golgi Apparatus
  • from Camillo Golgi
  • consists of a series of flat, membrane-bound sacs
  • parallel to each other
  • packages and secretes products of E.R.
  • "packaging counter of the cell"
  • one side receives from the E.R.
  • inner sacs modify molecule
  • other side transports out of the cell
Lysosomes
  • is derived from the Greek word "breaking body"
  • "suicidal bags of the cell"
  • fuse with food vacuoles and digest the cell contains with the enzymes
     Lysosomal Storage Disease
  • Pompe's Disease - accumulation of glycogen
  • Tay-Sach's Disease - accumulation of lipids
Vacuoles
  • fluid-filled cavities in the cytoplasm containing crystals, inorganic salts, sugars, insoluble particles, and excess water
  • bounded by a membrane
  • usually acts as storage organelles
Food Vacuoles
Contractile Vacuoles

In Plants:
     Centarl Vacuole - for growth
- contain pigments that attract insects
- contain toxic substances to protect from plant-eating insects

Peroxisomes
     - catalase
              - breaks down hydrogen peroxide
Hydrogen Peroxide
     - very toxic
     - product of cellular metabolism

ORGANELLES PECULIAR TO PLANT CELLS

1. Cell Wall
          - protection
          - 3 layers : primary layer
                              middle lamella
                              secondary layer
2. Plastids
          - pigment-containing storage organelles
Chloroplasts: red, yellow, green, violet, orange
Leucoplasts: colorless

Thylakoids  - disk-shaped structures
                     - stroma
                     - grana 

Saturday, August 7, 2010

CELLS

THE CELL THEORY

Zacharias Jansen (1588-1631)
- invented one of the microscope's first prototype

Robert Hooke (1635-1703)
- reported some clear drawings of the plant cells
- introduced the term cell after observing boxlike structures from cork slices

Anton van Leeuwenhoek (1632-1723)
- reported the discovery of blood cells, sperm cells

*FORMULATED AFTER 200 YEARS AFTER THE INVENTION OF MICROSCOPE

Lorenz Oken (1779-1851)
- postulated that all organisms originate from and consist of cells

Robert Brown (1773-1858)
- discovered the nucleus

Felix Dujardin (1801-1860)
- sarcode, living substance within the cells was discovered (1835)
- the term was changed to protoplasm by Jan Evangelista Purkinje (1787-1869)

Matthias Schleiden (1804-1881)
- said that plants are made up of cells

Theodore Schwann (1810-1882)
- said that animals are made up of cells

Rudolf Virchow (1821-1902)
Concluded that
- the cell is the basic and structural unit of life
- every cell is formed from pre-existing cell


THREE PRINCIPLES OF THE CELL THEORY
  • All organisms are composed of one or more cells
  • Cells are the basic unit of organization of all organisms
  • Cells arise only by division of a previously existing cell

Sunday, August 1, 2010

CHEMICAL COMPOUNDS IN THE LIVING SYSTEM

Compounds
- a bigger molecule formed by atoms

2 Main Groups

Organic Compounds
- compounds that contain carbon atoms bonded to hydrogen or oxygen atoms

Inorganic Compounds
- compounds that lack carbon atoms


Inorganic Compounds

Water HOH
- 2/3 of our total body weight is water
- universal solvent

Acids
- releases one or more hydrogen ions (H+)
ex:
Hydrochloric acid (HCI)
Sulfuric acid (H2So4)

Base or Alkaline
- releases one or more hydroxyl ions (OH-)
ex:
Sodium hydroxide (NaOH)
Ammonium hydroxide (NH4OH)

pH Scale
- measures how acidic or how basic a substance is.
0-6 : substance is acidic
ex: battery acid
7 : neutral
ex: water
8-14 : substance is basic
ex: baking soda

buffers - resist changes in the pH of the chemical system
*Important Biological Buffers
- bicarbonates
- phosphates
- organic molecules (amino acid)

Salts
- form when an acid and a base react.
- hydrogen ion+hydroxyl ion = salt (table salt)+water

Neutralization Process - positive ion of an acid reacts with the negative ion of a base


Organic Compounds

Carbohydrates : compounds contaning carbon, hydrogen, and oxygen in the ration of 1:2:1

Monosaccharides - simplest form of carbohydrates
- glucose, fructose, and galactose are examples

Glucose
- most common hexose in the body
- sometimes reffered to as blood sugar, dextrose, and grape sugar
- indespensable component of blood

Fructose
- sugar that accounts for the sweeteness of ripened fruits

Galactose
- monosaccharides found in milk

Five-carbon sugars (pentose)

Ribose
- important component of ribonucleic acid (RNA)
Deoxyribose
- important component of deoxyribonucleic acid (DNA)


Disaccharides
- reffered to as the double sugars
- made up of two monosaccharide units
Dehydration Synthesis
- formation of a disaccharide from 2 monosaccharide units with the
removal of a water molecule

Examples:

Maltose (malt sugar)
-formed by the reaction of 2 glucose units

Sucrose
- common table sugar
- formed by the reaction of one molecule of glucose and one molecule of fructose

Lactose
- milk sugar
- formed when one molecule of glucose reacts with one molecule of galactose

Polysaccharides
- composed of a large number of monosaccharide units

Starch
- common component of plant protoplasms
- soluble in water

Glycogen
- found in bodies of animals
- excess glucose units stored temporarily

Cellulose
- similar to starch
- insoluble in water
- part of the plant cell wall


Lipids : composed of carbon, hydrogen, and oxygen but contain much less oxygen in proportion to carbon and hydrogen

2 Basic Units

Glycerol
Fatty acids

2 Kinds of Fats

Saturated Fats
- are solid at solid temperature
- examples are butter, lard, and animal fats
- promotes a condition called atherosclerosis

Unsaturated Fats
- remain liquid at room temperature
- not harmful to one's health
- examples are corn oil, olive oil , and other vegetable oils.


Proteins
- most diverse in the structure and function among organic compounds

peptide bond - formed between the amino group of amino acids and the carbon group of the next
amino acid.

Classes of Proteins

a. Structural Protein e. Transport Protein
b. Contractile Protein f. Hormonal Protein
c. Storage Protein g. Receptor Protein
d. Defensive Protein h. Catalytic Protein


Nucleic Acid
- serve as blueprints for proteins that ultimately control the chemical processes in a cell.
- nucleotide is composed of a five-carbon sugar, a phosphate group, and a
nitrogen-containing base pair.