2.8 cell respiration (anaerobic)

cell respiration definition

cell respiration definition

the controlled release of en from organic cmpds in a serires of enz catalysed metabolic pathways to allow the maximal release of en in a usable form , atp

atp structure

adenosine (nitrogenous grp) attached to C1

pentose (ribose)

3 phosphates

O in bw

C2 differentiates bw deoxyribose and ribose

phosphorylation

the addition of 1 phosphate

adp + p → atp

uses en

hydrolysis: releases en , 1p

glucose = pri respiratory substrate

respiration = breakdown of glucose to form atp

glucose → glycolysis → pyruvate, atp → either aerobic or anaerobic resp in mito or cyto

glycolysis

glucose broken down → 2 pyruvate + net gain of 2 atp

no co2 prod, no atp req

lactate fermentation: anaerobic resp in humans

glucose → glycolysis (+2atp) → 2 pyruvate → lactate fermentation (releases 2 NAD+ so glycolysis can continue) → 2 lactate total 4 atp at the end

happens in cytoplasm of cells

imptance: small yield of energy, but can be prod quickly. enables a person to continue exercising for a short period of time during a period of great exertion, maximising power of muscle contractions.

occurs when the rate of breakdown of sugars for atp is faster than the rate at which o2 is supplied by blood.

what happens to lactate

brought by blood to liver. some lactate is oxidised to release en → used to convert rest of lactate to glucose. then transported back to muscles

oxygen debt

the extra o2 req to restore normal body functioning after exercise

yeast: alcoholic fermentation

glucose → glycolysis (+2atp) → 2 pyruvate → alcoholic fermentation (+2CO2) → 2 acetaldehyde → 2 ethanol

eg bioethanol: ethanol prod by living organisms — used as a renewable en source, fuel in vehicles

respirometer

used to measure rate of o2 uptake by organism

co2 prod by organism is abosorbed by an alkali, eg. KOH.

conditions to maintain: temp to avoid vol changes due to temp fluctuations