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Question 1

what is meant by photosynthesis?

Answer 1

• the reaction plants use to absorb light for their source of energy.

Question 2

where does photosynthesis take place?

Answer 2

• in the leaves of a plant

Question 3

state the word equation for photosynthesis

Answer 3

• carbon dioxide + water = glucose + oxygen

Question 4

state the balanced symbol equation for photosynthesis

Answer 4

6 CO2 + 6 H2O = C6 H12 O6 + 6 O2

Question 5

what kind of reaction is photosynthesis?

Answer 5

• endothermic, as it takes in energy.

Question 6

is leaf a tissue, organ or organ system?

Answer 6

organ

Question 7

is xylem a tissue, organ or organ system?

Answer 7

tissue

Question 8

are roots, stem and leaves a tissue, organ or organ system?

Answer 8

organ system

Question 9

state 5 uses of glucose

Answer 9

1. respiration - takes place in the mitochondria
2. storage - excess glucose is converted into soluble starch and stored away.
3. proteins - amino acids combine with nitrate ions to make protein.
4. cellulose - cell walls contain cellulose, which gives it strength.
5. oils or fats - glucose produced in photosynthesis which is converted to fats and oils. it is also used as storage for energy.

Question 10

by which process do we get energy from?

Answer 10

• respiration

Question 11

state three reasons why organisms need energy?

Answer 11

1. movement
2. to keep warm
3. chemical reactions to build larger molecules

Question 12

where does respiration take place?

Answer 12

• in all living cells

Question 13

what kind of reaction is respiration?

Answer 13

• exothermic, as it releases energy

Question 14

what does the chemical symbol C6 H12 O6 stand for?

Answer 14

glucose

Question 15

what does the chemical symbol O2 stand for?

Answer 15

oxygen

Question 16

what does the chemical symbol CO2 stand for?

Answer 16

carbon dioxide

Question 17

what does the chemical symbol H2O stand for?

Answer 17

water

Question 18

what is meant by aerobic respiration and how much energy is transferred?

Answer 18

• in aerobic respiration, glucose reacts with oxygen
• this produces carbon dioxide and water, so a lot of energy is transferred.

Question 19

what is the word equation for aerobic respiration?

Answer 19

• glucose + oxygen = carbon dioxide + water + energy

Question 20

what is meant by anaerobic respiration and how much energy is transferred?

Answer 20

• when there is a shortage of oxygen, muscles respire anaerobically.
• it releases much less energy than aerobic respiration

Question 21

state the word equation for anaerobic respiration

Answer 21

glucose = lactic acid + energy

Question 22

which type of respiration takes place in yeast cells? state the name and word equation.

Answer 22

• anaerobic respiration
• fermentation
• glucose = ethanol + carbon dioxide

Question 23

what is the economic importance of fermentation?

Answer 23

• it is used to make alcoholic drinks, such as beer.
• additionally, in bread, the dough rises.

Question 24

what happens to the heart rate when you exercise and respire more?

Answer 24

• it increases to pump more oxygenated blood.

Question 25

what happens to the breathing rate when you exercise and respire more?

Answer 25

- it increases as we breathe more frequently

Question 26

what happens to the breathing volume when you exercise and respire more?

Answer 26

- it increases as we take deeper breaths.

Question 27

what is meant by oxygen debt?

Answer 27

- Oxygen debt is the amount of extra oxygen the body needs after exercise to deal with the accumulated lactic acid. - During long periods of vigorous activity, the lactic acid causes the muscles to become fatigued,so the body has to remove the lactic acid from the muscles.

Question 28

what is metabolism?

Answer 28

- the sum of all the chemical reactions in a cell or the body.

Question 29

give examples of metabolic reactions that take place in the body.

Answer 29

1. large molecules made from small ones: - lots of small glucose molecules are joined together to form starch, glycogen and cellulose. - lipid molecules are made from one molecule of glycerol and three fatty acids. - glucose is combined with nitrate ions to make amino acids, which are then made into proteins. 2. large molecules are broken down into small ones: - glucose is broken down in respiration, which transfers energy to power all the reactions that make molecules. - excess protein is broken down in a reaction to produce urea, which is excreted in the urine.

Question 30

why is anaerobically transferring energy from glucose not the best way?

Answer 30

- as lactic acid builds up in the muscles, which can get painful. - additionally, long periods of exercise cause muscle fatigue, which is when the muscles get tired and stop contracting efficiently.

Question 31

what is inverse square law?

Answer 31

- the inverse law links intensity and distance. - the law is when light intensity decreases in proportion to the square of the distance. - light intensity = 1/d2 - as distance doubles, light intensity goes down by a factor of 4.

Question 32

describe the four factors that affect the rate of photosynthesis

Answer 32

the limiting factors at a particular time depends on the environmental conditions: - at night, light is the limiting factor. - in winter, temperature is the limiting factor - if it is sunny (warm and bright) CO2 is the limiting factor. - chlorophyll could also be a limiting factor as it causes chloroplasts to become damaged or not make enough chlorophyll.

Question 33

name the four factors that affect the rate of photosynthesis

Answer 33

1. light intensity 2. carbon dioxide concentration 3. temperature 4. amount of chlorophyll

Question 34

how does light intensity affect the rate of photosynthesis?

Answer 34

- not enough light slows down the rate of photosynthesis. - as the light level increases, the rate of photosynthesis increases steadily.

Question 35

how does the carbon dioxide concentration affect the rate of photosynthesis?

Answer 35

- less carbon dioxide slows down the rate of photosynthesis. - as carbon dioxide increases, the rate of photosynthesis increases as well

Question 36

how does temperature affect the rate of photosynthesis?

Answer 36

- as the temperature increases, the enzymes involved in photosynthesis work faster, so the rate increases. - if we keep increasing the temperature, the enzymes will denature and plants cannot photosynthesise.

Question 37

how does chlorophyll affect the rate of photosynthesis?

Answer 37

- the amount of chlorophyll in a plant can be affected by disease or environmental stress. - this causes chloroplasts to become damaged or to not make enough chlorophyll.