Biochemistry SOL BIO 3 b,c

BIO 3 b, c OBJECTIVE: TSW investigate and understand the chemical and biochemical principles essential for life. Key concepts include- b)the structure and function of macromolecules c)the nature of enzymes.

Most life processes are a series of chemical reactions influenced by environmental and genetic factors.

Metabolism the sum of all biochemical processes

2 Metabolic Processes Anabolism- the building up of complex molecules Catabolism- the breaking down of complex molecules

–The main components of a living cell are: Carbon Hydrogen Nitrogen Oxygen -Phosphorus -Sulfur

Inside every cell is a concentrated mixture of thousands of different macromolecules forming a variety of specialized structures that carry out cell functions, such as: – energy production – transport – waste disposal – synthesis (creation) of new molecules – storage of genetic material.

Organic Compounds CompoundsCARBON organicCompounds that contain CARBON are called organic. Macromoleculesorganic moleculesMacromolecules are large organic molecules.

Carbon (C) Carbon4 electronsCarbon has 4 electrons in outer shell Carboncovalent bonds 4Carbon can form covalent bonds with as many as 4 other atoms (elements) H, O, N, or CUsually with H, O, N, or C Example: C 6 H 12 O 6 (sugar)Example: C 6 H 12 O 6 (sugar)

Macromolecules Large organic molecules.Large organic molecules. POLYMERSAlso called POLYMERS. MONOMERSMade up of smaller “building blocks” called MONOMERS. Examples:Examples: 1. Carbohydrates 2. Lipids 3. Proteins 4. Nucleic acids (DNA and RNA)

1. Carbohydrates Small sugar moleculeslarge sugar moleculesSmall sugar molecules to large sugar molecules. Examples:Examples: A.monosaccharide B.disaccharide C.polysaccharide

1. Carbohydrates A.monosaccharide: one sugar unit Examples:glucose (Examples:glucose (C 6 H 12 O 6 blood sugar)deoxyriboseribose galactose (milk sugar) fructose (honey) glucose

B. disaccharide: two sugar unit Example:sucrose = glucose + fructoseExample:sucrose = glucose + fructose fructoseglucose

C.polysaccharide: many sugar units Examples:starch (bread, potatoes)Examples:starch (bread, potatoes) glycogen (beef muscle) cellulose (lettuce, corn) chitin (exoskeletons) glucoseglucose glucoseglucose glucoseglucose glucoseglucose cellulose

The primary functions of carbohydrate macromolecules are to: – provide and store energy.

2. Lipids not soluble in waterGeneral term for compounds which are not soluble in water. are soluble in hydrophobic solventsLipids are soluble in hydrophobic solvents. Remember:“stores the most energy”Remember: “stores the most energy”

2. Lipids Examples:1. FatsExamples:1. Fats 2. Phospholipids 3. Oils 4. Waxes 5. Steroid hormones 6. Triglycerides

5 functions of lipids:5 functions of lipids: 1.Long term energy storage (fat) 2.Protection against heat loss (insulation) 3.Protection against water loss & germs (oils & waxes) 4.Chemical messengers (hormones & steroids) 5.Major component of membranes (phospholipids)

Triglycerides: 1 glycerol 3 fatty acidsTriglycerides: composed of 1 glycerol and 3 fatty acids. H H-C----O H glycerol O C-CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 3 = fatty acids O C-CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 3 = O C-CH 2 -CH 2 -CH 2 -CH =CH-CH 2 -CH 2 -CH 2 -CH 2 -CH 3 =

fatty acidsThere are two kinds of fatty acids you may see on food labels: 1.Saturated fatty acids: no double bonds (bad) 2.Unsaturated fatty acids: double bonds (good) O C-CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 3 = saturated O C-CH 2 -CH 2 -CH 2 -CH =CH-CH 2 -CH 2 -CH 2 -CH 2 -CH 3 = unsaturated

3. Proteins (Polypeptides) Amino acids (the building blocks of protein) 2 kinds of amino acids -essential & non-essential amino acids - Essential amino acids cannot be synthesized by our body & need to be obtained through our diet

7 functions of proteins:7 functions of proteins: 1.Storage:albumin (egg white) 2.Transport: hemoglobin 3.Regulatory:hormones 4.Movement:muscles 5.Structural:membranes, hair, nails 6.Enzymes:cellular reactions 7. Defense:antibodies

A protein’s structure depends on its specific jobA protein’s structure depends on its specific job The sequence of amino acids and the shape of the chain are a consequence of attractions between the chain’s parts. The sequence of amino acids and the shape of the chain are a consequence of attractions between the chain’s parts.

Four levels of protein structure:Four levels of protein structure: A.Primary Structure (1°) B.Secondary Structure (2°) C.Tertiary Structure (3°) D.Quaternary Structure (4°)

A.Primary Structure (1°) peptide bonds.Amino acids bonded together by peptide bonds. aa1aa2aa3aa4aa5aa6 Peptide Bonds Amino Acids (aa)

B.Secondary Structure (2°) primary structurecoilspleats hydrogen bonds3-dimensional folding arrangement of a primary structure into coils and pleats held together by hydrogen bonds.

B.Secondary Structure (2°) Two examples: Alpha Helix Beta Pleated Sheet Hydrogen Bonds

Alpha Helix Beta Pleated Sheets

C.Tertiary Structure (3°) Secondary structuresbendfold more complex 3-D arrangementSecondary structures bend and fold into a more complex 3-D arrangement. “subunit”.Called a “subunit”.

C.Tertiary Structure (3°) Alpha Helix Beta Pleated Sheet

Subunit: Alpha Helix & Beta Pleated Sheets joined together

D.Quaternary Structure (4°) Composed of 2 or more “subunits”. enzymes (hemoglobin)Example: enzymes (hemoglobin) 3° subunits

Subunits

Enzymes: Special Proteins

4. Nucleic acids Nucleic acids (DNA and RNA) control cell activities by controlling protein synthesisNucleic acids (DNA and RNA) control cell activities by controlling protein synthesis

4. Nucleic acids Two types:Two types: 1. deoxyribonucleic acid (DNA-double helix) 2. ribonucleic acid (RNA-single strand) Nucleic acidsNucleic acids nucleotides are composed of long chains of nucleotides

4. Nucleic acids Nucleotides:Nucleotides: phosphate group sugar (5-carbon) nitrogenous bases adenine (A) thymine (T) - uracil (U) RNA cytosine (C) guanine (G)

Nucleotide O O=P-O OPhosphate Group Group N Nitrogenous base (A, G, C, or T) (A, G, C, or T) CH2 O C1C1 C4C4 C3C3 C2C2 5 Sugar Sugar(deoxyribose)

DNA - double helix P P P O O O P P P O O O G C TA

Most cells function best within a narrow range of temperature and pH.Most cells function best within a narrow range of temperature and pH. At very low temperatures, reaction rates are too slow.At very low temperatures, reaction rates are too slow. High temperatures or extremes of pH can irreversibly change the structure of proteins and alter their function.High temperatures or extremes of pH can irreversibly change the structure of proteins and alter their function.