cellular metabolism

metabolism

sum of all chemical reactions in the body

cellular metabolism

sum of all chemical reactions occurring in a cell

anabolism

small molecules are built into large ones; requires energy

catabolism

larger molecules are broken down into smaller ones; releases energy

dehydration synthesis

smaller molecules are bound together to for larger ones; h2O produced in the process; used to produce poly saccharides, proteins, and triglycerides; example of anabolism

hydrolysis

used to decompose carbohydrates, proteins, and lipids; uses h2O to split the substances; reverse dehydration synthesis; example of catabolism

enzymes

control rates of both catholic and anabolic reactions; greatly increase reaction rates

enzymes (protein catalysts)

Globular proteins that catalyze specific reactions
• Increase rates of chemical reactions
• Lower the activation energy necessary to start reactions
Not consumed in the reaction, so are used repeatedly
• Each enzyme is specific to a particular substrate
• Ability to recognize substrate depends on shape of active
site of enzyme

cofactor

non-protein substance that combines with the enzymes to activate it

• some help fold active site into proper conformation

• some help bind enzyme to substrate

• can be ion, element, or small organic molecule

coenzyme

organic molecule that acts as cofactor

• most are vitamins, which are essential organic molecules that humans must get from their diet

cellular respiration

process that transfers energy from molecules, and makes it available for cellular use

atp (adenosine triphosphate)

molecule that carries energy in a form the cell can use; main energy carrying molecule in a cell; energy from atp breakdown is used for cellular work

atp 3 portions

adenine, ribose, 3 phosphates

2nd and 3rd phosphate are attached by

high energy bonds

when atp loses last phosphate it becomes

adenosine dephosphate (adp)

when adp can be converted back into atp by attaching a 3rd phosphate

phosphorylation (requires energy from cellular respiration)

cellular respiration of glucose occurs in 3 interconnected
reaction sequences

glycolysis (anaerobic), citric acid cycle (aerobic), electron transport chain (aerobic)

occurs in a metabolic cycle in which the final product reacts to replenish original substrate

citric acid cycles

anaerobic reaction

do not require O2, makes little atp

aerobic reaction

requires O2; make most of ATP

glycolysis

break down of glucose into 2 smaller molecules; anaerobic, occurs in cytosol

glycogen

the stored form of glucose

glycogenolysis

glycogen is broken down into glucose to provide immediate energy

glycogenesis

the process of synthesizing glycogen from glucose