Photosynthesis

Question 1

Define photosynthesis

Answer 1

Photosynthesis refers to the process of capturing light energy to power the production of glucose and oxygen from carbon dioxide and water.

Question 2

Define the mesophyll cell

Answer 2

The mesophyll refers to a plant cell type found in leaves that contains large amounts of chloroplasts.

Question 3

Define the chloroplasts

Answer 3

The chloroplasts refers to the membrane-bound organelle only found in plant and photoautotroph cells that is the site of photosynthesis.

Question 4

Define the chlorophyll

Answer 4

The chlorophyll refers to the chemical found in the thykaloids of chloroplasts. Responsible for absorbing the light energy in photosynthesis.

Question 5

Define the stoma

Answer 5

The stoma refers to a small pore on the leafs surface that opens and closes to regulate gas exchange.

Question 6

Define the Light Dependent stage in photosynthesis

Answer 6

The light dependent stage refers to the first stage of photosynthesis where light energy splits water molecules into oxygen and hydrogen inside the thykaloid membranes.

Question 7

Define thykaloids

Answer 7

Thykaloids refer to a flattened sac-like structure located inside the chloroplasts. Each thykaloid consists of a chlorophyll-containing membrane enclosing a lumen.

Question 8

Define Granum/Grana

Answer 8

granum refers to a stack or collective of thykaloids.

Question 9

Identify the inputs of the LDR

Answer 9

The inputs of the Light Dependent Stage of photosynthesis include: 12 water or H20 molecules, 12 NADP+ and 18 ADP + P+.

Question 10

Identify the outputs of the LDR

Answer 10

The outputs of the Light Dependent Stage of photosynthesis include: 6 oxygen(o2) molecules, 12 NADPH and 18 ATP.

Question 11

Define the Light Independent Stage of photosynthesis

Answer 11

The light independent stage refers to the second stage of photosynthesis where carbon dioxide is used to form glucose in the stroma of the chloroplast. AKA the Calvin Cycle.

Question 12

Explain the location of the LIR

Answer 12

The location of the light independent reactions is known as the stroma.

Question 13

Explain the inputs of the LIR

Answer 13

The inputs of the Light Independent Stage include: 6 carbon dioxide(CO2) molecules, 12 NADPH and 18 ATP.

Question 14

Explain the outputs of the LIR

Answer 14

The outputs of the Light Independent Stage include: glucose(c6h12o6), 6 water molecules, 12 NADP+ and 18 ATP + Pi+.

Question 15

Explain a summary of what occurs in the Light Independent Reactions

Answer 15

During the duration of the LIR, carbon dioxide is collected from the stomata in leaves enters a cyclic reaction, the carbon, undergoes reactions powered by ATP and NADPH to produce a series of carbon-based molecules. A specific carbon contributes to the formation of glucose and water is formed as well.

Question 16

Explain a summary of what occurs in the Light Dependent Reactions

Answer 16

During the duration of the LDR, sunlight excites an electron within the chlorophyll, water absorbed by a plants roots hairs is split into O2 and H+ as it donates one electron to the chlorophyll. Excited electron and H+ ion from water lead to production of co-enzymes known as NADPH and ATP. Oxygen is released and co-enzymes are ready for second stage of photosynthesis.

Question 17

Identify the chemical equation for photosynthesis

Answer 17

the chemical equation for photosynthesis is carbon dioxide + water (sunlight) > glucose + water.

Question 18

Define Rubisco

Answer 18

Rubisco refers to a pivotal enzyme involved in initial carbon fixation during the light-independent reactions in photosynthesis.

Question 19

Define carbon fixation

Answer 19

Carbon Fixation refers to the process in living organisms where inorganic carbon, typically to do with carbon dioxide, is converted into organic compounds such as glucose, carbon fixation is an essential part of the LIS of photosynthesis.

Question 20

Define Photorespiration

Answer 20

Photorespiration refers to the wasteful process in plants initiated by Rubisco that limits photosynthesis.

Question 21

Identify the two factors that influence whether Rubisco binds to CO2 or O2.

Answer 21

The two factors that affect whether Rubisco binds or not is temperature and substrate concentration.

Question 22

Explain how the two factors affect the chance of Rubisco binding

Answer 22

The two factors are temperature and substrate conc. Substrate concentration - the more substrate that is present, the greater chance it has to undergo a reaction. However, when a plant needs to conservve water it will close it’s stomata, causing O2 to build up inside cells and increasing contribution of photorespiration. Temperature - At regular or low temperatures fondness for CO2, is far greater than that of O2. At higher temperatures, the affinity for O2 is greater, leading to Rubisco binding oxygen more often.

Question 23

Explain the concept of C3 plants

Answer 23

C3 plants refer to plants with no evolved adaptation to minimise photorespiration

Question 24

Explain the concept of C4 plants

Answer 24

C4 plants refers to plants that minimise photorespiration by separating initial carbon fixation and the remainder of the Calvin Cycle over (SPACE).

Question 25

Define bundle-sheath cells

Answer 25

bundle-sheath cells refers to a plant cell type that is the site of most of the Calvin Cycle in C4 plants.

Question 26

Define CAM plants

Answer 26

CAM plants refer to plants that minimise photorespiration by separating initial carbon fixation and the remainder of the Calvin cycle between night and day (TIME).

Question 27

Identify the factors affecting the rate of Photosynthesis

Answer 27

Light, Temperature and pH, Carbon dioxide, Water and Enzyme Inhibition.

Question 28

Define CRISPR

Answer 28

CRIPSR refers to short, clustered repeats of DNA found in prokaryotes which protects them from viral invasion.

Question 29

Define CRISPR-associated protein 9

Answer 29

Cas-9 refers to an endonuclease that creates a blunt end end cut at a site specified by guide RNA (gRNA).

Question 30

Explain potential CRISPR-Cas 9 changes towards crops

Answer 30

Some potential crop changes include: adjust stomata to improve CO2 uptake, greater herbicide resistance and changing C3 plants to CAM or C4 plants.