(a)
All organisms respire. The ATP produced as a result of respiration is used as the energy currency of the cell.
[ 2 ]
(i)
Name the stages in which chemiosmosis occurs in respiration and in photosynthesis.
respiration
photosynthesis
[ 2 ]
[Maximum number: 1]
Which of these processes will require ATP?
1 transport of water in the xylem
2 semi-conservative replication of DNA
3 facilitated diffusion of amino acids into the cell
A
1, 2 and 3
B
1 and 2 only
C
2 and 3 only
D
2 only
[Maximum number: 1]
In which of these organelles is ATP synthesised?
[Maximum number: 3]
Respiration is a process that results in the synthesis of ATP. The ATP can be used within the cell for energy-requiring reactions and processes.
There are four stages in aerobic respiration: glycolysis, the link reaction, the Krebs cycle and oxidative phosphorylation.
(a)
Chemiosmosis is a process that occurs in mitochondria during aerobic respiration and in chloroplasts during photosynthesis.
Describe the differences between the process of chemiosmosis in mitochondria and the process of chemiosmosis in chloroplasts.
[ 3 ]
(a)
ATP is synthesised from ADP and in a phosphorylation reaction.
State the two different ways in which this phosphorylation reaction occurs in aerobic respiration.
[ 2 ]
(a)
Within a mammalian cell, ATP can be produced in a number of ways, including:
- substrate level phosphorylation during the Krebs cycle
- oxidative phosphorylation.
Table 7.1 compares both processes.
Complete Table 7.1.
Use a tick if the statement is correct or a cross (x) if the statement is incorrect. The first row has been done for you.
Table 7.1
[ 3 ]
(a)
ATP can be converted to ADP and inorganic phosphate by the enzyme ATPase. State the type of reaction taking place.
[ 1 ]
(a)
In respiration, most ATP is synthesised during oxidative phosphorylation. Some ATP is made by substrate-linked reactions in glycolysis and Krebs cycle.
Describe how ATP is made by substrate-linked reactions.
[ 2 ]