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Flashcards in Organisms and energy Deck (23)
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1
Q

what is respration

A

respiration is a process used by all living organisms that releases the energy in organic molecules

2
Q

Explain how the human circulatory system facilitates respiration

A

a) glucose and oxygen diffuses from capillaries into respiring cells
b) carbon dioxide diffuses from respiring cells into capillaries

3
Q

Define diffusion

A

the net movement of particles from an area of high concentration to an area of lower concentration.

4
Q

Demonstrate an understanding of how aerobic respiration uses oxygen to release energy from glucose and how this process can be modelled using the word equation for aerobic respiration

A

aerobic respiration uses oxygen from the air to release energy from glucose. the products of aerobic respiration are carbon dioxide and water.

glucose + oxygen > carbon dioxide + water (+ energy)

5
Q

Investigate the effect of exercise on breathing rate and heart rate

A

your heart rate and breathing rate increase when you exercise. the harder you exercise the more these rates increase.

6
Q

Explain why heart rate and breathing rate increase with exercise

A

during exercise, muscle cells are respiring faster. this means that they need more oxygen and glucose, and release more carbon dioxide:
> a faster heart rate means that blood is pumped faster around the body. the blood takes oxygen and glucose to cells faster and removes carbon dioxide faster
> a faster breathing rate means that oxygen can be taken into the body at a faster rate and carbon dioxide can be released faster

7
Q

Calculate heart rate, stroke volume and cardiac output, using the equation cardiac output = stroke volume * heart rate

A

cardiac output = stroke volume * heart rate

8
Q

Demonstrate an understanding of why, during vigorous exercise, muscle cells may not receive sufficient oxygen for their energy requirements and so start to respire anaerobically

A

muscle cells may not receive sufficient oxygen for their energy requirements and so start to respire anaerobically. anaerobic respiration releases the extra energy the cell needs but cant get from aerobic respiration.

9
Q

Demonstrate an understanding of how anaerobic respiration releases energy from glucose and how this process can be modelled using the word equation for anaerobic respiration

A

anaerobic respiration is the release of energy form glucose without using oxygen. this produces lactic acid.

glucose > lactic acid (+ energy)

10
Q

Recall that the process of anaerobic respiration releases less energy than aerobic respiration

A

anaerobic respiration releases less energy from each molecule of glucose than aerobic respiration

11
Q

Describe how a build-up of lactic acid requires extra oxygen to break it down. This is called excess post-exercise oxygen consumption or EPOC (formerly known as oxygen debt)

A

lactic acid isn’t removed from the body. it builds up in muscle and blood, and must be broken down after exercise. excess oxygen is needed which is known as EPOC

12
Q

Explain why heart rate and breathing rate remain high after exercise

A

to bring extra oxygen into the body. some of this is needed to break down lactic acid produced from anaerobic respiration during the race.

13
Q

Describe how the structure of a leaf is adapted for photosynthesis

A

a) large surface area to capture as much light as possible for photosynthesis.
b) containing chlorophyll in chloroplasts to absorb light energy needed for photosynthesis.
c) stomata for gas exchange. allows carbon dioxide to be diffused into the leaf. and oxygen and water vapour to be diffused out of the leaf (carbon dioxide, oxygen and water vapour)

14
Q

Demonstrate an understanding of how photosynthesis uses light energy to produce glucose and how this process can be modelled using the word equation for photosynthesis

A

photosynthesis is the process that plants use to make glucose. during this chemical reaction, light energy is used to combine carbon dioxide and water.

carbon dioxide + water > glucose + oxygen

15
Q

Demonstrate an understanding of how limiting factors affect the rate of photosynthesis

A

a) light intensity - Increasing the light intensity will boost the speed of photosynthesis.
b) CO2 concentration - Even if there is plenty of light, a plant cannot photosynthesise if there is insufficient carbon dioxide.
c) temperature - If it gets too cold, the rate of photosynthesis will decrease. Plants cannot photosynthesise if it gets too hot.

16
Q

Investigate how factors, including the effect of light intensity, CO2 concentration or temperature, affect the rate of photosynthesis

A

by measuring the rate at which oxygen is given off by a piece of pondweed. you can use this to investigate the effect of temperature using warm and cold water baths, light intensity using bright and dim lights, carbon dioxide concentration by adding different amounts of sodium hydrogen carbonate to water

17
Q

explain the process of transpiration

A

transpiration is the evaporation of water from inside leaves out into the air. it causes water to move up the plant from the roots.

1) evaporation of water vapour from leaves
2) draws water out of the leaf cells and xylem
3) draws water up the xylem from the roots
4) causes water to enter the roots by osmosis

18
Q

Explain how water, glucose and mineral salts are transported through a plant

A

a) mineral uptake in roots by active transport - mineral salts cannot enter the root cells from soil water by diffusion because there is a higher concentration of mineral salts in the cells than in the soil. so the root cells have to use energy to transport mineral salts into the cells against their concentration gradient.
b) the role of the xylem and phloem vessels
> water and dissolved minerals enter plants through their roots from the soil water.
> water and dissolved minerals from the roots travel in xylem to the rest of the plant
> glucose, produced by photosynthesis in leaves, is converted to sucrose, which is transported in phloem to the rest of the plant.

19
Q

Describe how root hair cells are adapted to take up water by osmosis

A

have long extensions, that stretch out in the soil, giving them a large surface area where osmosis can take place which means that more water molecules can cross the cell membrane into the cell at the same time

20
Q

Define osmosis as the movement of water molecules from an area of higher concentration of water to an area of lower concentration of water through a partially permeable membrane

A

the movement of water molecules from an area of higher concentration of water to an area of lower concentration of water through a partially permeable membrane

21
Q

Investigate osmosis

A

osmosis can be investigated using potato strips or red onion cells in solutions of different concentrations

22
Q

Investigate the distribution of organisms in an ecosystem, using sampling techniques including:

A

a) pooters - for collecting animals smaller than the inlet tube. suck on the mouthpiece draws the animal in through the inlet tube. the net stops the animals from getting into the mouth
b) sweep nets/pond nets - for collecting large animals, sweep through grass and bushes or through water in pond or stream
c) pitfall traps - for collecting small ground-living animals
d) quadrats - can be used to sample plants or animals that don’t move to much

23
Q

how do you measure environmental factor in a ecosystem

A

a) temperature - probe connected to a data logger, or a thermometer.
b) light probe connected to a data logger, or a light meter
c) mix a sample of soil with distilled water, then measure the pH of the solution with universal indicator