Bioenergetics

Question 1

What is the word equation for aerobic respiration?

Answer 1

Oxygen+ glucose -> carbon dioxide+ water

Question 2

What is the symbol equation for aerobic respiration?

Answer 2

6O2+ C6H12O6 -> 6CO2+ 6H2O

Question 3

Define breathing

Answer 3

The physical process of inhaling and exhaling air in and out of lungs

Question 4

Define respiration

Answer 4

The chemical, exothermic reaction where glucose and oxygen chemically react to release energy for cellular reactions. Goes on in every cell continuously.

Question 5

What do animals need energy from respiration for?

Answer 5

. Keeping a constant body temperature
. Muscle contractions
. Building molecules

Question 6

Give examples of why plants need glucose from respiration for?

Answer 6

.For respiration
.Making amino acids- glucose is combined with nitrate ions to make amino acids
.Make cellulose- converted to cellulose for plant cell walls
.Stored as oils or fats
.Stored as starch

Question 7

What is the word equation for anaerobic respiration?

Answer 7

Glucose -> lactic acid + energy

Question 8

Define anaerobic respiration

Answer 8

The incomplete breakdown of glucose and so releases less energy than aerobic respiration making lactic acid

Question 9

What are the negatives of anaerobic respiration?

Answer 9

. Releases less energy than aerobic because the glucose isn’t fully oxidised
. Produces lactic acid which is toxic

Question 10

What is oxygen debt?

Answer 10

After anaerobic respiration, you have to pay back the oxygen to break down the lactic acid into CO2.

Question 11

When would plants respire anaerobically? Give an example.

Answer 11

Plants that grow in areas of low oxygen e.g marshes

Question 12

What is the name of when plants and yeast respire anaerobically?

Answer 12

Fermentation

Question 13

What is the word equation for fermentation?

Answer 13

Glucose -> carbon dioxide+ ethanol+ energy

Question 14

What is an enzyme?

Answer 14

Biological catalysts, they control the rate of chemical reactions

Question 15

Define metabolism

Answer 15

Sum of all the reactions in the cell of your body

Question 16

Name 2 examples of exothermic reactions

Answer 16

. Respiration
. Breaking down proteins into urea

Question 17

Is photosynthesis an endothermic or exothermic reaction?

Answer 17

Endothermic.

Question 18

What are the 4 factors that affect the rate of photosynthesis?

Answer 18

-Carbon dioxide concentration
-Light intensity
-Temperature
-Amount of chlorophyll

Question 19

At night, what is usually the limiting factor in photosynthesis?

Answer 19

Light

Question 20

In winter, what is usually the limiting factor for photosynthesis?

Answer 20

Temperature

Question 21

If it’s warm and bright, what is usually the limiting factor for photosynthesis?

Answer 21

Carbon dioxide concentration.

Question 22

How can the amount of chlorophyll in a plant be affected?

Answer 22

Disease (e.g tobacco mosaic disease) or lack of nutrients.
These factors lead to chloroplast being damaged or to not make enough chlorophyll. Less light absorbed.

Question 23

Describe the relationship between light and rate of photosynthesis and why.

Answer 23

As light intensity increases so does photosynthesis until a point. Beyond that, it won’t make a difference because either carbon dioxide or temperature will be the limiting factor.

Question 24

Describe the relationship between carbon dioxide and rate of photosynthesis.

Answer 24

As carbon dioxide increases so does rate of photosynthesis up to a point. After that, it makes no difference as light and/or temperature will be the limiting factor.

Question 25

Describe the relationship between temperature and rate of photosynthesis and why.

Answer 25

If temperature is too low- the enzymes needed for photosynthesis work more slowly. Rate of photosynthesis increases with temperature until around 45 degrees where the enzymes start to denature.

Question 26

Explain an experiment to to measure effect of light intensity on the rate of photosynthesis.

Answer 26

1) Canadian pondweed put in a glass tube with water in. 2)Put a source of white light at a specific distance away from the pondweed. 3)Leave the pondweed to photosynthesis for a set amount of time. Oxygen released will collect in capillary tube 4)The syringe is used to draw up the gas bubble in the tube up alongside a ruler to measure length of gas bubble- proportional to volume produced. 5)Repeat the exact same thing- calculate mean. 6)Repeat experiment with light source at a different distance.

Question 27

Explain the inverse square law.

Answer 27

Light intensity is inversely proportion to the square of the distance. E.g if you third the distance, light intensity increase by 9. If you triple the distance, light intensity decreases by 9.

Question 28

What is the calculation to measure light intensity.

Answer 28

1/ distance squared.

Question 29

How can you artificially create the ideal conditions in a greenhouse?

Answer 29

. Artificial light can be used after the sun goes down to increase time for photosynthesis . In winter, heaters keep ideal temperature . In summer, ventilation keeps cools it down . Carbon dioxide can be increased by using paraffin heaters- as the paraffin burns, carbon dioxide is a by product.

Question 30

Evaluate how cost efficient keeping ideal temperatures in a greenhouse is?

Answer 30

It costs money but if the farmer keeps conditions just right for photosynthesis, crops will grow at a faster rate so more will be sold. If done more than needed, wastes money.

Question 31

True or false: Plants respire.

Answer 31

True. All living things respire.

Question 32

When does anaerobic respiration occur in humans?

Answer 32

When doing vigorous exercise and body can't supply enough oxygen to your muscles. Does anaerobic as well as aerobic respiration.

Question 33

When is fermentation used in the food industry?

Answer 33

. In bread making- carbon dioxide from fermentation makes bread rise . In beer and wine making- process produces alchohol

Question 34

Why do you respire more when exercising?

Answer 34

Your muscles contract more than usual so you need more energy.

Question 35

What's muscle fatigue?

Answer 35

After long periods of exercise muscles get tired and stop contracting efficiently.

Question 36

How does your body get more oxygen in during exercise?

Answer 36

.Breathing rate and breath volume increases to get more oxygen in the blood .Heart rate increases to get oxygenated blood around the body faster.

Question 37

Apart from converting lactic acid into carbon dioxide, what's another way to cope with high levels of lactic acid?

Answer 37

Blood transports the lactic acid to the liver. In the liver, lactic acid is converted back to glucose.