3.5.2.1 respiration

What is the role of the mitochondria?

- the site of aerobic respiration

- ADP is phosphorylated

- ATP is made

what is gas exchange?

the diffusion of gasses from an area of high concentration to an area
of low concentration

what is respiration?

- energy stored in complex organic molecules

- used to make ATP

- energy is released when C-H
bonds of respiratory substrates
are broken

- energy used to
synthesise ADP + PI to form the ATP

why is respiration important?

- respiration produces ATP to release energy

- for active transport, protein synthesis etc

where does the co-enzyme NAD carry a H atom?

transfers H atom from glycolysis, the link reaction, kerbs cycle to oxidative phosphorylation

where does the co-enzyme FAD transfer the H atom?

transfers a H atom
from the krebs cycle
to oxidative phosphorylation

where does the coenzyme A transfer an acetyl group?

transfers an acetyl group from
the link reaction to the krebs cycle

what type of biochemical is a co enzyme?

Nucleic acid

does the Inter membrane space of a mitochondria have a high or low concentration of H+?

- high

- impermeable to H+ except for ATP synthase

does the matrix have a low conc of H+ and what does it contain

- yes

- matrix has many enzymes

what does the loop of DNA in the mitochondria code for?

- ATP synthase
- enzymes
- electron carriers

qhat does the outer membrane of the mitochondria do?

carries for pyruvate

label the mitochondria

[look at notes cuz Quizlet wants my money and it's not getting it]

what is the first stage of respiration?

glycolysis

where does glycolysis take place?

- cytoplasm

- does not require oxygen
It is an anaerobic process

what is the process of glycolysis?

1) phosphorylation of glucose to glucose phosphate using 2 ATP

2) hydrolysed to 2x triose phosphate

3) oxidation of triose phosphate to produce 2 pyruvate

4) net gain of two ATP (substrate level phosphorylation). 4 produced and 2 used

5) 2 reduced NAD produced

6) 2 pyruvate produced

why is glucose not used by the mitochondria?

- glucose is broken down during glycolysis in the cytoplasm

- glucose cannot cross mitochondrial membrane

- pyruvate crosses mitochondrial membrane by active transport into matrix from cytoplasm

what is substrate level phosphorylation?

- formation of ATP from ADP + Pi in glycolysis and the Krebs cycle.

(formation of ATP without chemoosmosis and an ETC)

what is the second stage of respiration?

link reaction

where does the link reaction happen? *

- matrix of the mitochondria

- pyruvate is actively transported into matrix

what is the process of the link reaction?*

1) oxidation of / H removed from pyruvate to acetate

2) CO2 reaction

3) acetate combines with coenzyme A forming acetyl coenzyme A

4) link reaction produces reduced NAD (picks up H)

what are the products of the link
reaction for each molecule of glucose?

- link reaction occurs twice for every molecule of glucose
so:

2x reduced NAD,
2x CO2 molecules,
2x acetyl COA

where does the Krebs cycle occur?

matrix of mitochondria

what is the process of the Krebs cycle?

1) acetyl coenzyme A (2C) combines With 4C molecule to form 6C citrate (CO-enzyme A is released for LR)

2) citrate is oxidised

3) krebs cycle produces reduced co-enzymes 3x reduced NAD per turn Ix reduced FAD per turn

4) 1 ATP produced in Krebs cycle (substrate level phosphorylation) per turn

5) 2 CO2 molecules produced per turn by decarboxylation

what are the products of the krebs cycle per molecule of glucose?

- cycle occurs twice per molecule of glucose
x6 reduced NAD
x 2 reduced FAD
X 2 ATP
x 4 CO2

where does oxidative phosphorylation occur?

cristae of mitochondria

what is the process of oxidative phosphorylation? *

1) electrons + protons released from reduced co-enzymes NAD / FAD

2) electrons pass along carriers / through series of redox reactions

3) energy released by electrons

4) energy used by electron carriers to actively pump protons from matrix into intermembrane space

5) protons diffuse into matrix via ATP synthase down a electrochemcial gradient

6) energy released by electrons used in ADP phosphorylated to ATP by pi

7) in matrix at end of ETC, oxygen is final electron & proton acceptor

8) so protons, electrons and oxygen combine to form water

how do you calculate the quotient?

CO2 produced / O2 consumed

RQ carbohydrates

1.0

protein quotient

0.9

lipids quotient

0.7125

anaerobic respiration quotient

> 1

what is a respiratory substrate?

an organic substance that can be oxidised in respiration to release energy for the synthesis of ATP

how are proteins respired?

- excess proteins hydrolysed to amino acids, deaminated (amino group removed)

- ketos can be converted to: pyruvate, acetate or enter Krebs cycle directly

how are fatty acids respired?

- long C-H chain is broken into 2 acetyl groups

- reduced NAD and reduced FAD are formed

- 2 acetyl groups enter Krebs cycle

when are fatty acids respired?

- fatty acids need lot of oxygen as the final acceptor of H+ and e-

- fatty acids from hydrolysis of lipids converted to acetyl coenzyme A

- there are respired during periods of extended low intensity exercise