Download Biology Section 2 Molecules of Life Carbohydrates Carbohydrates

Biology Section 2
Molecules of Life
Carbohydrates
 Carbohydrates- 1 carbon:2 hydrogen:1 oxygen
 Energy or structural material
 Monosaccharides
o Monosaccharide- contains 1:2:1 of C:H:O, written as (CH2O)n where n is
3 to 8
o Glucose, fructose, and galactose are monosaccharide
o Differing structure gives different properties- isomers
 Disaccarides and Polysaccharides
o Disaccharides- two monosaccharides
o Polysaccharides- three or more monosaccharides
o Starch for quick energy, cellulose for structure
Proteins
 Carbon, oxygen, hydrogen, nitrogen- linked amino acids
 Amino Acids
o Carbon links hydrogen, carboxyl, amino, and R (main difference) group
 Dipeptides and Polypeptides
o Dipeptide- two amino acids
o Peptide bond- condensation reaction between amino acids
o Polypeptides- long string of amino acids
o Protein shape influenced by bonding, solvent, temperature
 Enzymes
o Enzymes- RNA or protein catalysts
o Physical fit between enzyme and substrate (substance being catalyzed)
o Active site- folds
o Slight change in shape weakens chemical bonds
o Enzymes can be modified
Lipids
 Lipids- large, nonpolar, energy-storing
 Fatty Acids
o Fatty acid- carboxyl head, carbon chain tail
o Saturated- only single bonds
o Unsaturated- some double bonds
 Triglycerides
o 3 molecules fatty acid, one molecule glycerol (alcohol)
o Saturated have high melting points, unsaturated are liquid at room
temperature
 Phospholipids
o Form cell membranes due to insolubility
 Waxes
o Long fatty-acid and alcohol chain, waterproof
 Steroids
o Four fused carbon rings- hormones, cholesterol
Nucleic Acids
 Nucleic acids- transfer information
Biology Section 2
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Deoxyribonucleic acid (DNA)- determines characteristics of organism
Ribonucleic acid (RNA)- enzyme or makes proteins
Both are polymers made of nucleotides
Nucleotides- phosphate, five-carbon sugar, ring-shaped nitrogenous base