exam revision - photosynthesis & respiration

Question 1

define photoautotrophic

Answer 1

organisms which use light to make organic molecules such as sugars, and turns simple compounds to organic compounds.

Question 2

photosynthesis equation

Answer 2

6CO+6H2O–light–chlorophyll–>C6H12O6+6O2

Question 3

What is photosynthesis

Answer 3

the process in which plants, algae and some bacteria and protists use energy from the sun to make organic molecules.

Question 4

Inputs of photosynthesis

Answer 4

water, ADP, NADP+, carbon dioxide, ATP, NADPH

Question 5

Outputs of photosynthesis

Answer 5

oxygen, ATP, NADPH, glucose, ADP, NADP+

Question 6

What are thylakoids in chloroplast

Answer 6

the fluid filled flattened discs, where the chlorophyll is embedded, this is where the light dependent stage occurs

Question 7

what are grana in chloroplast

Answer 7

stacks of thylakoids (singular granum), contains chlorophyll

Question 8

what are stroma in chloroplast

Answer 8

the fluid inside chloroplast that bathes the grana, contains enzyme, light independent stage occurs here.

Question 9

What is endosymbiosis

Answer 9

the chloroplast/ mitochondria is believed to have once been free-living cells. It is suggested that one of these was engulfed by another microbial cell. This is a benefit as:

• the host cell gained a source of sugar production
• the engulfed cell gained a protective environment and additional source of energy. Evidence includes chloroplast/ mitochondria has its own DNA.

Question 10

What are the two stages of photosynthesis

Answer 10

light dependent stage, light independent stage

Question 11

light dependent phase

Answer 11

which occurs in the thylakoid membranes of a chloroplast. Requires light energy which ‘drives’ the movement of electrons along the electron transport chain. Energy is captured from the sun, water is split into hydrogen ions, electrons and oxygen.
The light energy is converted to chemical energy, which its temporarily stored in ATP and NADPH

Question 12

light independent phase

Answer 12

also known as the Calvin cycle occurs in the stroma of the chloroplast. Does not need light to occur, but needs the light dependent phase for the ADP and NADPH in order for the Calvin cycle to occur.

Question 13

What factors effect photosynthesis

Answer 13

light intensity, type of light (wavelength), CO2 availability, water availability, temperature

Question 14

aerobic respiration equation

Answer 14

C6H12O6+6O2–>6CO2+6H2O+36ATP

Question 15

What is cellular respiration

Answer 15

is a catabolic energy yielding pathway. It is a process by which organisms break down energy rich molecules such as glucose releasing energy to be used to make ATP

Question 16

What are the steps of aerobic respiration

Answer 16

1. Glycolysis
2. transition reaction
3. kerb cycle
4. electron transport chain

Question 17

Explain the process of glycolysis including inputs and outputs

Answer 17

Glycolysis means ‘sugar splitting’, in this step, glucose is converted to pyruvate. It occurs in the cytosol, and glycolysis has two main functions, it produces ATP, NADH, and it produces pyruvate.
INPUTS - glucose, ADP+Pi, NAD+H
OUTPUTS - pyruvate, 2ATP, 2NADH

Question 18

Explain the process of transition reaction including inputs and outputs

Answer 18

the transition reaction links pyruvate with the kreb cycle, pyruvate is taken into the matrix and converted to CoA.
INPUTS - pyruvate
OUTPUTS - CoA

Question 19

Explain the process of the kreb cycle including inputs and outputs

Answer 19

the kreb cycle is a series of chemical reactions in the matrix of the mitochondria. It requires two turns to completely breakdown a molecule of glucose.
INPUTS - pyruvate
OUTPUTS - CO2, 2ATP, NADH, FADH

Question 20

Explain the process of the electron transport chain

Answer 20

occurs in the cristae of the inner membrane, this is where oxygen is used, and the energy from NADH and FADH are used to power pumps to move H atoms.
INPUTS - NADH, O2, FADH
OUTPUTS- 32ATP, H2O