Microbiology Chapter 6: Metabolism: Fueling Cell Growth

Metabolism

all chemical reactions necessary to maintain life

catabolism

breakdown of molecules

anabolism

building molecules

coenzyme/cofactor

compound helps enzyme, vitamin or mineral

major classes of enzymes

oxidoreductases, transferases, hydrolases, lyases, isomerases, ligases

oxidoreductases

cause losses or gains of O and H

transferases

transfer functional groups

hydrolases

split bonds with water

lyases

remove atoms without water

isomerases

rearrange molecules

ligases

join molecules

effects of temps and pH on enzymes

increase temp, speeds enzymes, denaturation occurs

decrease temp, slows enzymes

high or low pH disrupts structure of function of enzymes

competitive enzyme inhibitors

bind reversibly to the active site

noncompetitive enzyme inhibitors

bind to another spot called the allosteric site, can be reversible or irreversible

adenosine triphosphate

nucleic that is broken to release energy

ATP is made by

photosynthesis, aerobic and anaerobic respiration

aerobic respiration

breakdown of glucose w/ plenty of oxygen

anaerobic respiration

fermentation, breakdown of glucose w/ little oxygen

photosynthesis

light causes electrons in chlorophyll molecules to be excited from their regular orbit, they fall back down releasing energy

water is split into

electrons, oxygen, and hydrogens

oxidation of glucose equation

C6H12O6 + 6O2 → 6CO2 + 6H2O + 38 ATP

glycolysis

begins with glucose, phosphates added, molecule rearranged, split in half forming pyruvate. 1 into 2

Krebs Cycle

pyruvic acid + coenzyme A = acetyl CoA + oxaloacetic acid, CO2, NADH and FADH2

electron transport system

begins with NADH and FADH2, molecules split releasing H+ and e-. e- pass through protein series, hydrogens flow across membrane → energy released, energy is used to make ATP, while H+ and e- join without to form water

fermentation

lack of oxygen causes pyruvate to be converted into acids or alcohols, common lactic acid or ethanol

lipid breakdown

triglycerides are broken into glycerol and fatty acids. glycerol can enter krebs cycle while fatty acids go through beta oxidation, broken into 2-carbon fragments, then fragments enter the krebs cycle

protein breakdown

proteins are broken into individual amino acids then the amine group is removed, two carbon fragment then enters the krebs cycle.