B4 - Bioenergetics - Cognito Notes

Question 1

What is photosynthesis?

Answer 1

the absorption of light by chlorophyll in the chloroplast of a leaf

Question 2

What is the word equation of photosynthesis?

Answer 2

carbon dioxide + water -> glucose + oxygen

Question 3

What is the symbol equation of photosynthesis?

Answer 3

6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂

Question 4

What are the five reasons plants want glucose?

Answer 4

cellular respiration, cellulose (strengthen cell walls), starch (storage), amino acids (w/ nitrate ions = proteins), oils + fats (storage)

Question 5

How does light intensity affect photosynthesis?

Answer 5

photosynthesis rate plateaus, something else must be a limiting factor

Question 6

How does temperature affect photosynthesis?

Answer 6

Rate rises initially, then starts to drop after optimum temp due to enzymes denaturing

Question 7

How does carbon dioxide concentration affect photosynthesis?

Answer 7

photosynthesis rate plateaus, something else must be a limiting factor

Question 8

How does chlorophyll amount affect photosynthesis?

Answer 8

chlorophyll level within a plant can differ due to disease, environmental stress, or lack of nutrients

Question 9

What can be done to recreate the effectors of photosynthesis?

Answer 9

colder climates (greenhouses - including CO₂ pump for heat + CO₂, enclosed so lack of pests, farmers use fertilisers (enough nutrients), bit expensive though)

Question 10

What is the inverse square law?

Answer 10

states that the intensity of light decreases proportionally to the square of the distance from its source

Question 11

What is the formula for the inverse square law?

Answer 11

light intensity ⍺ 1/distance²

Question 12

What is cellular respiration?

Answer 12

an exothermic reaction which transfers energy from glucose and is continuously occuring in living cells

Question 13

How is energy from cellular respiration used?

Answer 13

build up larger molecules, muscular contraction (for movement), maintain body temp., for reactions (most of which are catalysed by enzymes)

Question 14

What is metabolism?

Answer 14

all chemical processes in an organism to maintain life

Question 15

What is aerobic respiration?

Answer 15

more common respiration, takes place when enough oxygen and continously

Question 16

Where does aerobic respiration take place?

Answer 16

mitochondria - site of respiration

Question 17

What is the word equation of aerobic respiration?

Answer 17

Glucose + oxygen -> carbon dioxide + water

Question 18

What is the symbol equation of aerobic respiration?

Answer 18

C₆H₁₂O₆ + 6O₂ -> 6CO₂ + 6H₂O

Question 19

How is aerobic and anaerobic respiration different?

Answer 19

aerobic is with oxygen, anaerobic is without oxygen

Question 20

What is anaerobic respiration?

Answer 20

less common respiration - only done when necessary (e.g. oxygen can’t keep up during vigorous exercise)

Question 21

What is the word equation of anaerobic respiration?

Answer 21

glucose -> lactic acid

Question 22

What is the word equation of anaerobic respiration in plants + yeast?

Answer 22

glucose -> ethanol + carbon dioxide#

Question 23

Why does our body need to carry out more aerobic respiration during exercise?

Answer 23

exercise requires more muscle movement, lung muscle contraction, oxygen pumped around body leading to heart mucle contraction - all of which requires energy from aerobic respiration

Question 24

Why does our body carry out anaerobic respiration during exercise?

Answer 24

if exercise gets too intense, there will be a lack of oxygen - anaerobic is the best option even though lactic acid is produced which causes a burning sensation

Question 25

How can we investigate the effects of exercise on our body?

Answer 25

breathing rate (how many times chest rises + falls in given amount of time (1 min)), heart rate (measure pulse w/ flacid on any artery in wrist/neck)