Unit 5 - energy transfer in and between organisms

Question 1

Stomata

Answer 1

Gaps on the lead surface to allow the mesophyll to access gases easily

Question 2

Light dependent reaction

Answer 2

Conversion of water to electrons and protons by light

Question 3

Photolysis

Answer 3

Splitting of water into electrons, protons and oxygen

Question 4

Photoionisation

Answer 4

Sunlight falling onto chlorophyll exciting electrons which enter the ETC

Question 5

Thylakoids

Answer 5

Disc like sacs in the chloroplast. Site of the light dependent reaction

Question 6

NADP

Answer 6

Coenzyme crucial in photosynthesis. Carrier of protons when reduced

Question 7

Light independent reaction

Answer 7

Conversion of RuBP into organic molecules. Follows movement of carbons and is cyclic

Question 8

StromA

Answer 8

fluid filling the chloroplast

Site of the light independent reaction

Question 9

Glycolysis

Answer 9

Conversion of glucose to pyruvate in both aerobic and anaerobic respiration

Question 10

Link reaction

Answer 10

Conversion of pyruvate acetate and then acetyl coenzyme A

Question 11

Kerbs cycle

Answer 11

Incorporation of acetylcoenzhne A into cycle that release NADH, FADH2, CO2 and ATP.

Question 12

Oxidative phosphorylation

Answer 12

Final stage of aerobic respiration.

Uses electrons from coenzyme carriers as well as proton movement to generate ATP

Question 13

Anaerobic respiration

Answer 13

Absence of oxygen
Used to regenerate NAD for glycolysis
Lactic acid produced in humans
Ethanol produced in plants

Question 14

Saprobionts

Answer 14

Decompose organisms by releasing minerals back into the mineral cycles

Question 15

Calorimetry

Answer 15

Method to measure chemical energy store of organisms

Question 16

Net primary productivity

Answer 16

Total energy store remaining after considering respiratory losses as well as excretion

Question 17

Nitrogen cycle

Answer 17

Involves ammonification
Nitrification 
Nitrogen fixation
Denitrification 
These ensure nitrate ions enter the food chain

Question 18

Mutualistic nitrogen-fixing bacteria

Answer 18

Turn nitrogen gas into ammonia. Living on plant roots, they get carbs and plants get amino acids

Question 19

Phosphorus cycle

Answer 19

Cycle that releases phosphate from rocks and oceans, is converted by plants and passed through the food chain

Question 20

Leaching

Answer 20

Movement of excessive amounts of nutrients into waterways

Question 21

Eutrophication

Answer 21

Process by which nutrient concentration in the water leads to algal bloom and development of putrid waterways

Question 22

Location of glycolysis

Answer 22

Cytoplasm

Question 23

Location of link reaction

Answer 23

Matrix

Question 24

Location of kerbs cycle

Answer 24

Matrix

Question 25

Location of electron transport chain and oxidative phosphorylation

Answer 25

In between outer and inner membrane of mitochondria

Question 26

How many net ATO molecules are produced during glycolysis

Answer 26

2

Question 27

How many ATP molecules released during link reaction

Answer 27

0

Question 28

How many ATP molecules released during Krebs cycle

Answer 28

1

Question 29

Name for the current theory by which respiration occurs

Answer 29

Chemiosmotic theory

Question 30

What do animals convert pyruvate into?

Answer 30

Triphosphate

Question 31

What are some methods used in intensive rearing of domestic livestock?

Answer 31

Use of hormones to increase growth rates

Selective breeding of animals to produce varieties that are more favourable

Question 32

In livestock how is the energy converted into biomass increased?

Answer 32

• Restrict movement - reduce muscle contraction
• keep environment warm - less energy used to warm the body
• control feeding - prevent the cow eating as much fibrous food
• exclude predators - prevent higher trophic levels

Question 33

Biomass

Answer 33

Total mass of a living material in a specific area at a given time
Can be measured in terms of mass of carbon or dry mass tissue per given area.
Dry biomass can be estimated using colorimetry

Question 34

Consumers

Answer 34

These obtain their energy and nutrients by feeding other organisms rather than using the suns energy directly.
Can be primary, secondary or tertiary.

Question 35

Producers

Answer 35

Photosynthetic organisms that manufacture organic substances using light energy, water, carbon dioxide and mineral ions

Question 36

What does the relative inefficiency of energy transfer between tropic levels explain?

Answer 36

• most food chains only have 4-5 levels due to limited energy available (not enough to support another level)
• total biomass decreases at high levels
• total amount of energy is less available moving up

Question 37

Net production to consumers calculation

Answer 37

Ingest food - (energy lost in faeces + respiratory loss)

Question 38

NPP equation

Answer 38

NPP = GPP - respiratory losses

Question 39

Gross primary production

Answer 39

Chemical energy store in plant biomass in a given area or volume

Question 40

Why is only 1% and 3% of the suns energy available to be converted into organic matter by plants?

Answer 40

• Over 90% of the suns energy is reflected back into space by clouds and dust or absorbed by the atmosphere
• not all wavelengths of light can be absorbed and used for photosynthesis
• light may not fall on a chlorophyll molecule

Question 41

Why is less that 20% of a producer/consumers NPP used by the next consumer in growth?

Answer 41

• some of the organism is not consumed
• some pairs are fibrous
• some energy is lost in excretory materials
• some is lost as heat from respiration to the environment