Download Organic Molecules: The Molecules of Life

Organic Molecules: The Molecules of Life
Organic molecules contain Carbon and Hydrogen
Carbon has 4 spaces for electron in its outer shell- so it can share electrons with at most
four other atoms
Ex) CH4, methane
Carbon atoms binds to other carbons atoms and form chains
Draw chain and Hs
Other elements that are found in the body include:
S sulphur
N nitrogen
O oxygen
P Phosphorous
K Potassium
Na Sodium
Ca Calcium
Main idea of biological molecules
Small molecules combine and form larger molecules
And the opposite, large molecules are broken down into smaller molecules
Small molecules
Also called
monomers
Monosaccharides
Ie) glucose
Amino Acids
nucleotides
Big molecules,
called polymers,
Carbohydrates
Ie) starch
Protein
Nucleic acids
Reactions
Making molecules called synthesis, sometimes called dehydration reaction
The equivalent of a water molecule is removed from the chemicals, so they are
“dehydrated”
Monomer- OH + H- Monomer polymer + H20
Taking molecules apart is called degradation of hydrolysis (water, splitting)Water is
added to the polymer and is divided between the monomers
Polymer + water monomer-OH + monomer -H
Carbohydrates
Carbon /hydrogen
Function
Short term storage and immediate source of energy in all animals
Also play structural role in plants, bacteria and insects
Carbohydrate structures also work with other types of biological molecules, like cell
recognition glycoproteins of cell membranes
Formula for Carbohydrate
CH2O
Generally, there are 2 hs for every C
Types
Simple:
Monosaccharides and disaccharides
Complex, Polysaccharides:
Starch, glycogen and cellulose
Simple mono and di sacs
Monossacharides/One monomers
Examples
Sugars with 5 carbons (called pentoses)
Ribose, deoxyribose
Sugars with 6 carbons (called hexoses)
Glucose – the sugar in our blood- break down of dietary carbohydrates
Fructose- from fruits
Galactose- part of milk
Disacchardides/Two monomers attached together
Glucose + glucose maltose- imp in brewing
Glucose and fructose sucrose (common sugar)
Glucose + galactose lactose
Complex Polysacchardides
Includes starch, glycogen and cellulose
They are long chains of glucose.
Starch
Storage form of carbs in plants. A potato is a special root that the plant will draw energy
from when needed. Doesn’t have many side branches. Is broken down during digestion
into glucose which we burn to make ATP.
Glycogen- storage of carbs in animals. Excess sugar is stored in the liver. This molecule
has many side branches. Glycogen is broken down into glucose when blood sugar is low.
Cellulose
Structural material for the cell walls of plants and bacteria
It is a chain of several thousand to over 10 000 glucose molecules
Chains form bundles of fibres, like yarn is made from many thread, or cables from many
wires.
Chemical Composition of cellulose makes it impossible for humans to digest.
(something to do with where the O2 is???)
known as fibre and important for the health of our digestive tract
Lipids
3 main groups
1- fats and oils
saturated and unsaturated fats
2- phospholipds
3- steroids
lipids in general
contain lots of energy
fats in animal bodies function as a long term energy storage
fatty tissue also covers our organs and protects them from injury
lipids do not dissolve in water
It is possible for us to digest fats because we emulsify them. Bile from our gall bladder is
secreted into our digestive tract and causes fat droplets to be broken down into small
drops of fat which makes it possible for digestive enzymes to efficiently react with.
Emulsification increases the surface area of the fat.
Fats and Oils
Fats and oils have no charge-they are neutral. We call them the neutral fats.
Fats- found in animals
We can think of body fat and the derived products of lard and butter
Oils are derived from plants. Ie) olive oil, canola oil….
Made of a glycerol backbone that has 3 fatty acid chains attached to it. Think of a big
letter E.
Fatty acids are chains of Carbon (16-18 or so)
have an acid group at one end, COOH.
There are two types of fatty acids and they give fats and oils their properties.
Saturated fatty acids
Saturated means completely full, full of H
There are no double bonds between carbons, so the other spaces are taken by H.
Sat fatty acids give fats there solid properties at room temp
Unsat fats
There are double bonds, which means there is less space for H. The chain is not full of H
The unsat fatty acids give oils their liquid qualities at room temp.
Hydrogenated fats or trans fats are vegetable oils that have H added so that they are solid
at room temp. These converted fats may be the most harmful of all.
Summary
Fats and oil
Made of glycerol and 3 fatty acids,
Fatty acids- un sat or sat.
Phospholipids
A phospholipid is like a fat. It has a glycerol backbone and 2 fatty acid chains. Instead
of a third fatty acid, it has a Phosphate group with a P and Nitrogen)
.The P group= head.
The fatty acids=tails
Head is polar- It has a charge
Tails are non-polar- no charge
Head- like water. Bcs it’s polar. Hydrophilic
Tails- don’t like water because they are neutral. Hydrophobic.
Phospholipids form the bilayer of the call member. Each layer is a row of P-lipids. The
head are on the outer edges because they like the water that is inside and surrounding the
cell. The tails are in the inside and are isolated from the water.
Steroids
Include cholesterol, estrogen, testosterone,
Basic structure- 4 carbon rings. And a functional group. Or an attached chemical group
that determines function.
Proteins
Functions:
Act as enzymes- speed up chemical reaction, ie digestive enzymes
Structural proteins- actin and myosin form muscle, collagen forms parts of cartilage and
tendons M-B, Elastin-gives stretching abilities to ligament (b-b), bladders, skin, blood
vessels.. keratin forms hair and finger nails
Plasma proteins allow movement of material through cell.
Blood proteins- hemoglobin carries O, albumin transports fats through blood
Antibodies- destroy foreign matter in body.
Proteins are made of amino acids
Strucure
Central C, bound to a H, with three groups attached
Left
Amino group NH2
right
acid grp COOH
“R” group
varies from AA to AA, give it unique props
There are twenty different AAs
As the letters of the alphabet can be combined to form an almost endless variety of
words, amino acids can be linked together in varying sequences to form a vast variety of
proteins.
Peptides
2 aas join to form a dipeptide. The bond btwn aa is a peptide bond and it is a hydrogen
bond, between the C=O of one AA and the N-H of another
A polypeptide is a chain of Aas.
Levels of Protein organization
First level, or Primary Structure
Linear order of Aas
Joined by peptide bonds
Second level, seconday structure
The chain may twist and form a spiral, or a helix,
It may fold and form a pleated sheet
Bonds across AAs are H bonds
Third Level, or teriary structure
Gives protein a globular shape
Tertiary structures have many bends and helixes
Bonds across AAs are covalent bonds (sharing of electrons) and sometimes disulphide
bonds, between 2 sulphurs in the R group
4th level/Quarternary Structue
This is when 2 or more polypeptides join to together to form a functioning protein.
Ex) hemoglobin-four globin polypeptides.
Importance of protein shape
Proteins wont work if they aren’t the right strucure
Factors that can change protein shape include heat and pH. In our bodies, there are
ranges of tolerances for proteins.
Nucleic Acids
Include DNA, RNA and ATP
DNA- deoxyribonucleic acid
Stores genetic info in cells
Replicates and transmits this info when needed-cell replication, protein synthesis
RNA has various forms. Primarily involved in protein synthesis.
DNA
2 strands
the 2 strands twist together in a double
helix
strands are chains of nucleotides
one nucleotuide has A phophate, a sugar
(deoxyribose) and a nitrogenous base.
The four bases are
Guanine cytosine– bond together- G-C
Adenine Thymine – bond together- A-T
RNA
Single stranded
Straight, no helix
Nucleotides have ribose as a sugar
Bases- has guanine, cytosine, adenine
and uracil (instead of Thymine)
Bonds: A-U, and G-C
ATP: Adenosine Triphosphate- Adenine, ribose and 3 phosphates.
Made in mitocoindria. Energy is held between the second and last P. When the bond is
broken, the energy is released.