Biochemistry

Photosynthesis Capture and use of solar energy to make food. Organelles convert light energy into chemical energy. 6CO 2 + 6H 2 O + NRG C 6 H 12 O 6 + 6O 2 (glucose)

How do animals get energy By eating plants, animals are able to release the stored energy in a plant. C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + NRG (glucose)

Carbohydrates Monomers and polymers of aldehydes and ketones Have numerous hydroxyl (OH) groups attached Many carbohydrates have the general formula C n (H 2 O) n

Cont. Monosaccharides Simplest carbohydrate molecules (simple sugars) Glucose Fructose

Cont. Disaccharides Cyclic forms of simple sugars linked by the loss of water. Example: Sucrose

Cont. Polysaccharides Many monosaccharide molecules linked Starches: water soluble digested by most animals Cellulose: insoluble in water, digested by only a few microorganisms

Starch Cellulose

Amino Acids and their polymers Any compound that contains amino (-NH 2 ) and carboxylic acid (-COOH)

Cont. 20 amino acids 9 “essential” amino acids must be included in diet. 11 “nonessential” amino acids can be synthesized by the body.

Cont. Peptides – any amino acid united w/ the carboxyilic acid group of another There always remains a free amino group and a free carboxylic acid group.

Cont. Any peptide w/ more than 10 a.a. is called a polypeptide Any peptide w/ more than 100 a.a. is called a protein A protein 100 a.a. long containing 20 different a.a. can be arranged times! Chains coil in 3 dimensions

Cont. Enzymes are proteins that act as biological catalysts Enzymes act on substrates Substrates bond w/ side chains of a.a. on the enzyme (active site) Enzymes have specific shapes, only allowing certain substrates to fit – Enzyme-Substrate complex (lock and key)

Lipids Triglycerides – triesters of glycerol w/ fatty acids H H + +

Cont. Important long-term storage molecules Fats vs. Oils Fats are solid at room temp. Oils are liquid at room temp. Both are esters

Cont. Fats and oils are hydrolysis easily in the presence of acids and bases. Hydrolysis w/ an alkali-metal hydroxide (NaOH, etc) is called saponification (process used to make soap.) Glycerol is a by-product.

Cont. Phospholipids – lipids that contain phosphate groups Molecules are two sided, one hydrophilic, the other hydrophobic These molecules together form the lipid bilayer of the cell wall

Hydrophilic Region Hydrophilic Region Hydrophobic Region

Cont. Waxes – Esters of long-chain fatty acids and long-chain alcohols. Low-melting stable solids Protects from water loss and attacks from microorganisms

Nucleic Acids Polymers found primarily in cell nuclei. Deoxyribonucleic acid (DNA) – Stores information needed to make proteins and governs the reproduction and growth of cells Ribonucleic acid (RNA) – Key role in the transmission of the information stored in DNA Made up of monomers called nucleotides Phosphate + 5-Carbon Sugar + Nitrogen base

Cont. The sugar unit in DNA is deoxyribose RNA contains ribose (one more oxygen) The nitrogen bases can be any one of four compounds Adenine, guanine, thymine (uracil in RNA), and cytosine DNA molecules consist of 2 polynucleotide chains wrapped into a spiral shape (helix)

Cont. Double-ringed bases must matched w/ a single-ringed base on the opposing strand. Hydrogen bonding is maximized in this configuration, making it the most stable arrangement.

Cont. DNA stores the instructions for building proteins (genes) Instructions are stored in “triplets” (three-letter base sequences) Each triplet is a code word for one of the 20 amino acids Example: ACC = Tryptophan

Cont. An amino acid can specified by more than one triplet code word, but a code word can never specify more than one amino acid Example : AAA and AAG both code for phenylalanine, but AAA could never code any other amino acid

Cont. Some code words terminate translations (ATT, ATC, and ACT) Amino acids are added to the protein until the “end” code word is reached Gene mutations occur by substitutions, additions, or deletions of nucleotides May result in faulty protein or no protein. The majority of gene mutations end with the protein being destroyed

Cont. Only 5% of human DNA is used to code for proteins 95% separates and interrupts gene coding sequences. DNA fragments are similar (have many of the same characteristics) but are not the same in family members

Cont. Recombinant DNA – way of manipulating genes. Genes are cut and spliced into new chains Insulin Bioluminescence Limb regeneration Cloning

Foreign gene cut by enzyme DNA strand sealed w/ enzyme to form recombinant DNA