Ch 4 Photosynthesis, cellular respiration and biotechnological applications

Question 1

What are the two stages involved in Photosynthesis?

Answer 1

1. light-dependent (grana)
2. light-independent (stroma)

Question 2

What are chloroplasts?

function and structure

Answer 2

site of photosynthesis
- double membrane (inner and outer)
- stacks of thylakoid called grana
- stroma (fluid within chloroplasts)

Question 3

What occurs in the light dependent stage of photosynthesis (grana)?

steps, inputs and outputs

Answer 3

• chlorophyll absorbs light energy
• energy splits water into hydrogen atoms and oxygen gas
• ATP and NADPH are produced

inputs
- sunlight initial input of energy to chlorophyll
- NADP+ unloaded coenzyme and acceptor of hydrogen atoms
- ADP unloaded coenzyme
- water supplier of electrons and hydrogen ions

outputs
- NADPH loaded coenzyme and donor of hydrogen ion
- ATP loaded coenzyme and energy supplier
- oxygen by-product of splitting water

Question 4

What is the Calvin cycle?

Answer 4

• requires CO2, H+ ions and ATP
• NADPH and ATP are recycled to grana
• H2O is an output produced by arrangement of CO2

Question 5

What occurs in the light independent stage of photosynthesis (stroma)?

Answer 5

• hydrogen provided by NADPH
• rubisco and energy from ATP and NADPH is converted to CO2 and glucose
• ADP and NADP+ return to grana for reuse

inputs
- NADPH loaded coenzyme and donor of hydrogen and electrons
- ATP loaded coenzyme and energy supplier
- carbon dioxide supplier of carbon and oxygen atoms

outputs
- NADP+ unloaded coenzyme and acceptor of hydrogen atoms
- ADP unloaded coenzyme
- glucose final product in photosynthesis

Question 6

What is Rubisco?

Answer 6

• enzyme that fixes CO2
• converts inorganic carbon dioxide molecules from air into organic carbon dioxide

Question 7

What is photorespiration?

Answer 7

• rubisco binds with O2 to make CO2 instead of binding with CO2
• reduces glucose production

Question 8

What are C3 plants?

definition and optimum environment

Answer 8

definition -> immediate organic product in Calvin Cycle in three-carbon molecule of phosphoglyceric acid
- thrive in cool to temperate environments

Question 9

What are C4 plants?

definition and optimum environment

Answer 9

• minimises photorespiration by separating initial CO2 fixation and Calvin Cycle in different cell types
• thrive in hot and sunny

carbon fixation
- occurs in mesophyll cells and fixed carbon moves to bundle-sheath cells

calvin cycle
- occurs bundle-sheath cells and fixed by Rubisco

Question 10

What are CAM plants?

definition and optimum environment

Answer 10

• CO2 fixation and Calvin cycle are seperated between night and day
• thrives in hot and dry environments

night time
- stomata is open and collects CO2 and reduces water loss

day time
- stomata closes and uses stored CO2 in calvin cycle

Question 11

What factors affect photosynthesis?

5 factors

Answer 11

• light availability and intensity
• light wavelength
• water availability
• carbon dioxide concentration
• temperature

Question 12

What is aerobic respiration?

definition, location, inputs and outputs

Answer 12

definition -> process of converting stored energy (glucose) into usable energy in form of ATP

glycolysis -cytosol
- inputs glucose, ADP + Pi, NAD+
- outputs pyruvate, ATP, NADH

krebs cycles - mitrochrondrial matrix
- inputs pyruvate, ADP + Pi, NAD+, FAD
- outputs CO2, 2 ATP, NADH, FADH2

electron transport chain - inner membrane of cristae
- inputs O2, NADH, FADH2, 2 ATP
- outputs H2O, NAD+, FAD, 26 or 28 ATP

Question 13

What is anaerobic respiration?

Answer 13

definition -> process where glucose is converted into ATP in absence of oxygen

Question 14

What are factors affecting cellular respiration?

3 factors

Answer 14

• temperature
• glucose availability
• oxygen concentration

Question 15

How can CRISPR-Cas9 be used to improve photosynthesis?