M3 Photosynthesis

Question 1

Explain how respiration in plants and animals depends upon the products of photosynthesis

Answer 1

• organic molecules (eg glucose) that are used in restorations are formed from the products of photosynthesis
• oxygen released as a by product in photosynthesis enables aerobic respiration

Question 2

How does the structure of chloroplasts enable them to carry out their functions?

Answer 2

• thylakoids arranged to form grana produce a large surface area for reactions
• thylakoids contain many photosynthetic pigments with enzymes and coenzymes for LDS
• stroma contains enzyme needed for LDS

Question 3

Define the term “photosynthetic pigment”

Answer 3

Large organic molecules that absorb light and convert it into a form of energy

Question 4

Explain the importance of photosynthetic pigments in photosynthesis

Answer 4

Range of Photosynthetic pigments each absorb a range of wavelengths. They each have a specific peak of absorption.

Question 5

What is the Importance of chlorophyll a?

Answer 5

Chlorophyll a is known as the “primary pigment”
Two main forms: P680 and P700
Obviously P680 has a peak absorption of 680nm etc.

Question 6

What are two main accessory pigments?

Answer 6

Carotene (reflects organge, absorbs blue)

Xanthophyll (reflects yellow, absorbs blue)

Question 7

Where does the light dependant stage take place?

Answer 7

Thylakoid membranes

Question 8

Where does the light in dependant stage take place?

Answer 8

Stroma

Question 9

Define the term autotroph and heterotroph

Answer 9

Autotrophs - organisms that absorbs inorganic substances and converts them into complex organic molecules
Heterotrophs - organism that obtains energy from large organic molecules