6. Photosynthesis

Question 1

What is the chemical formula for photosynthesis?

Answer 1

6 CO2 (g) + 6 H2O(I) + light energy 🡪 C6H12O6 (aq) + 6 O2 (g)

Question 2

Whats the goal of photosynthesis

Answer 2

To synthesize glucose

Question 3

Give an overview of the steps of photosynthesis

Answer 3

1. Capture light energy
2. Make ATP and NADPH
3. Use ATP and NADPH to make sugar

Question 4

Is photosynthesis anabolic or catabolic

Answer 4

Anabolic - small molecules combined

Question 5

Is photosyntheis endergonic or exergonic

Answer 5

Endergonic - stores energy

Question 6

What are the two stages of photsynthesis

Answer 6

1. Light dependent reactions
2. Light independent (dark) reactions

Question 7

Are plants autotrophs or heterotrophs

Answer 7

Autotrophs - produce their own food (glucose)

Question 8

Where does photosyntehsis occur

Answer 8

Photosynthesis mainly occurs in the leaves
- Stoma - pores
- Mesophyll cells

Question 9

Explain the use and location of the stomata

Answer 9

• Pores in a plants cuticle through which water vapor and gasses (CO2 and O2) are exchanged between the plant and the atmosphere
• Found on the underside of the leaf

Question 10

What is the structure of chloroplast

Answer 10

Double membrane structure
- Outer membrane
- Inner membrane

Question 11

Explain the components of chlorplasts

Answer 11

Thylakoid: a membrane bound flattened sac that looks like a poker chip
Granum: a stack of thylakoids (looks like a stack of poker chips)
Stroma: fluid surrounding the thylakoids
Thylakoid space: the space inside the thylakoid

Question 12

What is light

Answer 12

Light is a form of electromagnetic radiation that travels in waves

Question 13

What are the wavelengths of visable light

Answer 13

Visible light from the sun is composed of wavelengths of 750nm to 380nm (ROYGBIV)
- Red had the largest wavelengths
- Violent has the smallest

Question 14

What are the largest and smallest wavelengths called

Answer 14

Gamma rays are the smallest wavelengths
- High energy and high frequency
Radio Waves are the largest wavelengths
- Low energy and low frequency

Question 15

What are the three things that can happen to light

Answer 15

1. Absorption
2. Transmission
3. Reflection

Question 16

What is pigment

Answer 16

Pigment: a compound that absorbs certain wavelengths of visible light while reflecting others

Question 17

What colours do plants absorb

Answer 17

Plants absorb light (energy) of ALL COLOURS coming from the sun EXCEPT GREEN
- We see plants as green because this the only color REFLECTED to our eyes

Question 18

What colours do plants absorb

Answer 18

Plants absorb light (energy) of ALL COLOURS coming from the sun EXCEPT GREEN
- We see plants as green because this the only color REFLECTED to our eyes

Question 19

What pigrment do chloroplasts contain

Answer 19

Chloroplasts contain two types of pigment chlorophyll: a & b

Question 20

Which light does chlorophyll not absorb

Answer 20

Chlorophyll DOES NOT absorb green light

Question 21

What is the absorption spectrum

Answer 21

A graph that shows the amount of light in different wavelengths a compound can absorb

Question 22

What are the tree accessory pigments and their functions

Answer 22

1. Carotenoids - Responsible for yellow-orange coloured leaves in fall. Precursor of vitamin A, helpful for low vision
2. Xanthophylls - Responsible for yellow-coloured leaves in fall
3. Anthocyanins - Responsible for red-coloured leaves in fall

Question 23

What causes leaves to change colour in fall

Answer 23

The fall causes cooler temperatures meaning plants begin to break down chlorophyll colours and other pigments become viable

Question 24

What is Photosynthetically Active Radiation (PAR)

Answer 24

Light is absorbed from the entire visible spectrum
when all pigments are combined. Amount of light avalaible for photosynthesis