BIOENERGETICS

Question 1

what is the equation of photosynthesis?

Answer 1

carbon dioxide + water ——– oxygen + glucose + energy

Question 2

what is the balanced equation for photosynthesis?

Answer 2

6️⃣CO2 + 6️⃣H2O ——— 6️⃣O2 + C6H12O6 +ATP

Question 3

What type of reaction is photosynthesis?

Answer 3

Photosynthesis is an ENDOTHERMIC reaction because it takes in energy

Question 4

what absorbs the light energy for photosynthesis?

Answer 4

chlorophyll absorbs light energy

Question 5

Why do leaves adapt for photosynthesis?

Answer 5

leaves adapt to allow the maximum amount of photosynthesis to take place

Question 6

How do leaves adapt for photosynthesis?

Answer 6

🔹 Leaves have a large surface area to absorb as much light as possible.
🔹 Thin leaves make the path for diffusion for gasses quicker
🔹 They have stomata that can control gs exchange

Question 7

what are the 4 limiting factors?

Answer 7

☀️ Light
☀️ Temperature
☀️ Carbon dioxide levels
☀️ Chlorophyll levels inside the leaf

Question 8

How is light a limiting factor?

Answer 8

As the light intensity increases so do the rate of photosynthesis, light is a limiting factor because if there is less light, the rate of photosynthesis isn’t at its max.

Question 9

How is temperature a limiting factor?

Answer 9

As temp increases, so do photosynthesis rate, however, it will reach a max when it will get too hot and the enzymes required for photosynthesis denatures so the rate of photosynthesis decreases quick.

Question 10

How is CO2 concentration a limiting factor

Answer 10

CO2 levels can increase and decrease depending on the time of day, the time of year or even where the plant is. when the CO2 levels are not at its max, then it is seen as a limiting factor

Question 11

What factor limits the rate of photosynthesis often, when does this usually happen and how can we fix this. ( 6 marks )

Answer 11

🌾CO2 concentrations are usually the limiting factor because the atmosphere only has 0.04% of it in its atmosphere.
🌾On a sunny day, CO2 is the most limiting for plants because as the light intensity increases, the CO2 levels have to increase with it to maintain the increase of the rate of photosynthesis.
🌾to fix this we can put plants in greenhouses where the amount of CO2 can be increased artificially.

Question 12

How is chlorophyll a limiting factor?

Answer 12

If there is a smaller amount of chlorophyll, then the rate of photosynthesis is limited as there isn’t enough light energy being absorbed.

Question 13

®️what is the method of measuring the rate of photosynthesis?

Answer 13

Method
1. Put your 10cm piece of pondweed (cut edge at top) into a beaker of water.
2. Cover the pondweed with an inverted filter funnel – raised off the bottom of the beaker with plasticine.
3. Fill the measuring cylinder with water and gently position as in the diagram.
4. Use the ruler to position the beaker of pondweed 1 metre away from the light source.
5. Start the stopwatch and:
a. count and record the number of bubbles released in three minutes.
b. record the volume of gas produced and collected in the measuring cylinder in the same three minutes.
6. Record your results in a table
7. Move the light source so that the pondweed beaker is 80 cm away.
8. Refill the measuring cylinder with water and gently position as in the diagram.
Then repeat steps 5 and 6.
9. Repeat for distances of 60, 40 and 20 cm.

Question 14

what are the 5 uses of glucose in plants?

Answer 14

🍃 respiration
🍃 turning it into an insoluble starch for storage
🍃 used to produce oils and fats for storage
🍃 produce cellulose to strengthen the cell wall
🍃 to produce amino acids for protein synthesis

Question 15

What else is needed, other than glucose, to make proteins in a plant?

Answer 15

Nitrate ions from the soil are required as well as glucose.

Question 16

How does a carnivorous plant obtain nitrates?

Answer 16

nitrates are obtained by digesting the animal protein.

Question 17

what type of reaction is aerobic respiration?

Answer 17

it is an EXOTHERMIC respiration because it uses the oxygen and the glucose to transfer energy.

Question 18

Where do the chemical reactions of aerobic respiration take place?

Answer 18

the chemical reactions take place in the mitochondria and are controlled by enzymes

Question 19

what is the chemical equation for Aerobic respiration?

Answer 19

glucose + oxygen ——- carbon dioxide + water

C6H12O6 +6️⃣ O2 ——- 6️⃣CO2 + 6️⃣H20

Question 20

what can the glucose in aerobic respiration be used for?

5 ways

Answer 20

glucose may be used for:
👉🏽 maintaining the body temperature
👉🏽 turning smaller body cells into larger ones
👉🏽 for movement
👉🏽 to push materials against the concentration gradient (active transport)
👉🏽 to build sugars, nitrate and nutrients into amino acids and then proteins in plants

Question 21

when exercising, bodies require more oxygen and glucose, give 4 ways the body changes to do so?

Answer 21

💪🏽 heart rate increases
💪🏽 blood vessels supplying to the muscles dilate
💪🏽 breathing rate and depth of each breath increases
- this increases the intake of O2 and the release of CO2
💪🏽 muscles store glycogen, which changes back to glucose when exercising

Question 22

what is the word equation of anaerobic respiration in humans?

Answer 22

glucose —– lactic acid

Question 23

what is anaerobic respiration, and why does it happen?

Answer 23

anaerobic respiration is respiration without oxygen. it happens when not enough oxygen can be supplied to the muscle, usually when exercising.

Question 24

what creates lactic acid?

How do you get rid of lactic acid?

Answer 24

Lactic acid is formed when glucose doesn’t break down fully. When the muscles are tired they produce lactic acid.

The blood flowing through the muscle gets rid of lactic acid

Question 25

what is Oxygen debt?

Answer 25

After exercise, the lactic acid needs to be broken down into carbon dioxide and water. to do this, extra oxygen is required. the extra oxygen is called Oxygen Debt

Question 26

what is the equation for oxygen debt?

Answer 26

oxygen + lactic acid —– carbon dioxide + water

Question 27

How to microorganisms respire?

Answer 27

plants and microorganisms respire anaerobically

Question 28

what is the equation for anaerobic respiration in fungi?

Answer 28

glucose —- ethanol + carbon dioxide

C6H12O6 —- 2CH5OH + 2CO2

Question 29

what type of respiration happens in yeast?

Answer 29

anaerobic respiration which is called fermentation

Question 30

what is metabolism?

Answer 30

Metabolism is the sum of all chemical reactions happening in the cell or the body

Question 31

give 5 common metabolic reactions?

Answer 31

🌑 respiration
🌑 using glucose and nitrate ions to make amino acids for protein synthesis
🌑 the breakdown of excess proteins into urea for excretion
🌑 conversion of glucose into glycogen, cellulose and starch
🌑 formations of lipid molecules from one glycogen molecule and 3 fatty acid molecules

Question 32

what metabolic functions does the liver do?

4 points

Answer 32

the liver has many metabolic functions:
🏃‍♂️ it detoxifies toxin products such as ethanol from alcohol.
🏃‍♂️ passing the breakdown products into the blood so it can be excreted in urine by the kidney
🏃‍♂️ breaking down the old blood cells and storing the iron to create new blood cells
🏃‍♂️ getting rid of lactic acid

Question 33

how does the liver get rid of the lactic acid?

Answer 33

the lactic acid is transferred via blood to the liver where it is converted back into glucose. the oxygen debt is then repaid once all the lactic acid is turned into glucose and the glucose had turned back into carbon dioxide and water.
if the glucose isn’t, then it is turned into glycogen and stored in the liver until it is needed.