Biological Oxidation and Respiration

Question 1

Biological oxidation stages and aim

Answer 1

glycolysis
decarboxylation of pyruvate Krebs cycle
electron transport chain
aim is to generate Adenosine
triphosphate (ATP)

Question 2

oxidation and reduction

Answer 2

oxidation is the loss of electrons
reduction is the gain of electrons

Question 3

oxidoreductases

Answer 3

Enzymes involved in oxidation and reduction reactions
oxidases
dehydrogenases
oxygenases
hydroxylases
hydroperoxidases
reductases

Question 4

oxidases

Answer 4

O2 as the H or e- acceptor

Question 5

dehydrogenases

Answer 5

oxidise substrates by transferring one or more hydride ions

Question 6

reductases

Answer 6

catalyses reduction

Question 7

peroxidases

Answer 7

reduction of H peroxide and hydroperoxides

Question 8

oxygenases

Answer 8

incorporate O2 into organic substrates

Question 9

hydroxylases

Answer 9

add hydroxyl group to substrates

Question 10

Large DNA viruses replicate + transcript

Answer 10

bigger genomes = encode their own replication and transcription factors

Question 11

RNA viruses replicate + transcript

Answer 11

require RNA polymerase for transcription and these enzymes are not present in the host cell thus must be encoded by the virus

Question 12

Retroviruses

Answer 12

RNA viruses which utilize RNA-dependent DNA polymerase to replicate the RNA genome through a DNA intermediate (reverse transcription)

Question 13

Cellular respiration

Answer 13

form of biological oxidation which involves a series of redox reactions, the three stages of cellular respiration are glycolysis, Krebs cycle and oxidative phosphorylation (electron transport chain-ETC)

Question 14

Glycolysis, Krebs cycle and ETC occurs in

Answer 14

cytosol of a cell
mitochondria matrix
mitochondria matrix

Question 15

Glycolysis

Answer 15

anaerobic process
glucose is broken down to form pyruvate and minimal energy in the form of ATP is released.
2 ATP molecules used (stage 1 and 3)
produce 2ATP molecules (stages 7 and 10 each)
Energy is required in the form of ATP to split glucose intermediate (6 carbons) into
2 (3 carbon) intermediates. Thus the net gains of ATP from glycolysis are 2 ATP molecules. 2 pyruvate and NADH molecules also obtained from glycolysis.

Question 16

NADH

Answer 16

energy carrying molecule which is used as a cofactor in the electron transport chain to yield more ATP

Question 17

Decarboxylation of Pyruvate

Answer 17

Takes place between glycolysis and the Krebs cycle
pyruvate is decarboxylated coenzyme A is attached to it. The final product acetyl CoA is the molecule + enters the Krebs cycle

Question 18

Krebs Cycle

Answer 18

2 molecules of pyruvate generated by glycolysis are transported into the matrix
of the mitochondria.
Energy within pyruvate in the form of acetyl CoA is used to make 2 ATP, 6 NADH and 2 FADH2 via the Krebs cycle.

Question 19

Oxidative phosphorylation (ETC)

Answer 19

aerobic reaction
energy from 6 NADH and 2 FADH2 are converted into ATP with the help of 4 complexes.
NADH and FADH2 release
high energy electrons when they are transported.
Some of this energy is used to
pump hydrogen ions across the membrane which creates a chemiosmotic gradient.
ATP synthase is a channel protein that allows hydrogen ions to cross the membrane
and in the process it synthesises ATP and water. Without o2 this process cannot occur.

Question 20

Total ATP molecules made from cellular respiration

Answer 20

30-32 from glycolysis to ETC

Question 21

Metabolism

Answer 21

chemical reactions that place in a cell
3 aims of metabolism is to convert food/fuel to energy sources, utilize these energy sources to make macromolecules like proteins, nucleic acids and lastly the elimination of waste generated from these numerous reactions and processes

Question 22

2 types of metabolic reactions

Answer 22

Anabolism and Catabolism

Question 23

Catabolism

Answer 23

breaking down of molecules

Question 24

Anabolism

Answer 24

synthesis of compounds and molecules

Question 25

Enzymes

Answer 25

catalysts
they increase the rate of reaction and can be used to regulate reaction rate based on the external environment of the cell and signals received by the cell

Question 26

Chemiosmotic gradient

Answer 26

removal of protons from the matrix and deposition of protons in the intermembrane space creates a concentration difference of protons across the inner membrane