SECTION 2 : CARBON COMPOUNDS

Chapter 3 - Biochemistry

Carbon Bonding

Organic Compounds: made mostly of carbon atoms

Inorganic Compounds: do not contain carbon

Carbon can bond with itself: It can form straight

chains It can form branched

chains It can form rings

Functional Groups

Functional groups are the portion of a molecule that gives the molecule it’s particular properties. They are also active in a chemical reaction.

Functional GroupFormulas/ Chemical

StructuresCommon Name Biological Importance

CarboxylCarboxylic Acids

Polar – water solubleAcid in Amino AcidsAct as buffers in organisms

HydroxylAlcohols:Methanol, Ethanol

Polar – whole molecule is water soluble

Carbonyla. Aldehyde

b. Ketone

AldehydesGlyderaldehydeFormaldehydeKetonesAcetone

Polar – water solubleFunctional group in carbohydratesMetabolic intermediates

Ketones = nonpolar

Amino

AminesAmino Acids- Glycine

PolarFound in amino acidsAmmonia waste from protein

SulfhydrylCystine(amino acid)

Stabilizes proteins

PhosphateOrganic Phosphates

Polar; AcidicFound in DNA/RNAUsed in energy transport (ATP)

Large Carbon Molecules

Monomers: building blocks of organic molecules

Polymer: molecule made of multiple monomers that are linked together

Macromolecules: large polymers Ex: carbohydrates, lipids, proteins and nucleic acids

Making and Breaking Polymers

Condensation Reaction: monomers are linked to polymers and water is released

Hydrolysis: break down of polymers using water The reverse of a

condensation reaction

Energy Currency

Life processes require a constant supply of energy

Adenosine Triphosphate (ATP) a high energy compound found in cells Covalent bonds hold the

phosphate groups together The bond that attaches the

last phosphate group to the rest of the molecule is easily broken releasing energy for cell work

SECTION 3 : MOLECULES OF LIFE

Chapter 3 - Biochemistry

Molecules of Life

4 Molecules of Life Carbohydrates (sugars) Proteins (enzymes) Lipids (fats) Nucleic Acids (DNA and RNA)

Carbohydrates

Carbohydrates are organic compounds composed of carbon, hydrogen and oxygen General ratio is 1C:2H:1O or

(CH2O)n

Monosaccharides: monomer (building block) of a carbohydrate Examples: Glucose, Fructose

and Galactose All 3 monomers have the same

formula C6H12O6, but they each have different structures - isomers

Glucose

Fructose

Carbohydrates

Disaccharides: double sugar (two monosaccharides bonded together) The reaction that joins the two monosaccharides

together is called a condensation reaction

Examples:

SucroseLactose Sucrose

Carbohydrates

Polysaccharides: made of 3 or more monosaccharides bonded together Examples:

Glycogen (in animals): energy storage Stored in liver and muscle, made of glucose molecules

Starch (in plants): energy storage Made of glucose molecules

Cellulose (in plants): used for structure cell wall

Proteins

Proteins are organic compounds made of carbon, hydrogen, oxygen and nitrogen

Monomer = amino acids 20 different amino acids Functional groups of

amino acids: -COOH, NH2

What gives the amino acid its specific identity is it’s R-group R-groups can be simple

or complex

Proteins

Dipeptides are two amino acids bonded together The bond between amino acids is called a peptide

bond Peptide bonds are formed during a condensation

reaction

Proteins

Polypeptides: very long chains of amino acids

Form larger proteins, which are usually made of more than one polypeptide chain

4 levels of structure for polypeptides Primary: linear sequence

of amino acids Secondary: polypeptide

forms α-helices and β-sheets

Tertiary: R-groups interact with one-another

Quaternary: more than one polypeptide chain making a protein

Proteins

Enzymes: Protein (or RNA) molecules that act as biological catalysts

How enzymes work: Induced Fit Model of Enzyme Action

Enzyme reactions depend on the physical fit between the enzyme and its substrate (the reactant being catalyzed)

Active Site: portion of the enzyme that the substrate fits into

The linkage between the enzyme and the substrate causes a slight change in the enzyme’s shape which puts a strain on the substrate bonds

The enzyme releases the products and remains unchanged

Temperature and pH effect an enzyme’s activity

Enzyme Action

http://www.biotopics.co.uk/other/hienz.html

Lipids

Lipids: large, nonpolar organic molecules DO NOT dissolve in H20

Building blocks of lipids: Glycerol:

Functional group = -OH

Fatty Acids: unbranched carbon-chains Functional group = -COOH

Lipids

Fatty Acids Continued: Fatty acids can be saturated (each carbon is bonded to 4

other things – “full”)

Fatty acids can be unsaturated (when the carbon atoms form double bonds with each other in the carbon chain)

Lipids

Types of Lipids: Triglycerides: 3 fatty acids attached

to a glycerol

Phospholipids: 2 fatty acids attached to a glycerol, with a phosphate attached to the 3rd carbon of the glycerol Makes-up the cell membrane of cells

Hydrophilic head

2 Fatty acid tails

Lipids

Types of Lipids Continued Waxes:

Structural lipids Fatty-acid chains connect to an alcohol

chain Water-proof and provide protection

Steroids: Made of 4 fused carbon rings

Functions• Hormones (testosterone)• Found in cell membranes

(cholesterol)

Nucleic Acids

Nucleic Acids: store and transfer genetic information 3 parts of a nucleic acid:

Phosphate Group Sugar Nitrogenous Base

Three combined forms the nucleotide 2 types of Nucleic Acids

DNA: stores genetic information for an organism RNA: stores and transfers information from DNA that

is needed to make proteins