B4 Bioenergetics

Question 1

<p>Where does <strong>photosynthesis</strong> take place?</p>

Answer 1

<p>Photosynthesis takes place in the chloroplast of Plants and Algae</p>

Question 2

<p>Is Photosynthesis an <strong>Exothermic </strong>or <strong>Endothermic </strong>reaction?</p>

Answer 2

<p>Photosynthesis is <strong>endothermic </strong>meaning it <strong>requires energy</strong></p>

Question 3

<p>Where is the <strong>energy </strong>required for photosynthesis found?</p>

Answer 3

<p>Energy for photosynthesis is found from <strong>Sunlight</strong></p>

Question 4

<p>What is the <strong>symbol equation</strong> for photosynthesis?</p>

Answer 4

<p>6CO₂+6H₂O → C₆H₁₂O₆+6O₂</p>

Question 5

<p>What are the <strong>factors </strong>that affect the rate of photosynthesis?</p>

Answer 5

<ul>
	<li>Carbon Dioxide Concentration</li>
	<li>Temperature Light Intensity</li>
	<li>Chlorophyll concentration</li>
</ul>

Question 6

<p>At what temperature do <strong>enzymes </strong>start to <strong>denature </strong>in plants for Photosynthesis?</p>

Answer 6

<p>After 45 degrees, enzymes start to denature</p>

Question 7

<p>What is a <strong>limiting factor</strong>?</p>

Answer 7

<p>A limiting factor is something that <strong>restricts </strong>the <strong>rate of reaction</strong></p>

Question 8

<p>What different products can <strong>glucose</strong> be turned into?</p>

Answer 8

<ul>
	<li>Starch</li>
	<li>Proteins</li>
	<li>Cellulose</li>
	<li>Lipids (Fats and Oils)</li>
</ul>

Question 9

<p>What isthe<strong> inverse square law</strong>?</p>

Answer 9

<p>Light intensity = 1/distance²</p>

Question 10

<p>What is <strong>energy </strong>needed for?</p>

Answer 10

<ul><li>Homeostasis</li><li>Growth</li><li>Movement (Muscle Contraction)</li></ul>

Question 11

<p>What is the <strong>symbol equation</strong> for <strong>respiration</strong>?</p>

Answer 11

<p>C₆H₁₂O₆+ 6O₂→ 6CO₂+ 6H₂O (+ energy)</p>

Question 12

<p>Is <strong>respiration </strong>an <strong>endothermic </strong>or <strong>exothermic </strong>reaction?</p>

Answer 12

<p>Respiration is an <strong>exothermic </strong>reaction (Releases energy)</p>

Question 13

<p>What is the <strong>word equation</strong> for <strong>fermentation </strong><em>(anaerobic respiration in Plants and Yeast)</em>?</p>

Answer 13

<p>Glucose → ethanol + carbon dioxide</p>

Question 14

<p>What is the word equation for <strong>anaerobic</strong> respiration in <strong>animals</strong>?</p>

Answer 14

<p>Glucose → Lactic acid</p>

Question 15

<p>What is <strong>Metabolism</strong>?</p>

Answer 15

<p>Metabolism is the<strong> sum of all reactions</strong> that occur in an organism</p>

Question 16

<p>What are the responses the body does to increase the <strong>rate of respiration</strong>?</p>

Answer 16

<ul>
	<li>Increase in Breathing rate</li>
	<li>Increase in Breath volume</li>
	<li>Blood vessels dilate</li>
	<li>Increased heart rate</li>
</ul>

Question 17

<p>What is an <strong>Oxygen Debt</strong>?</p>

Answer 17

<p>Oxygen debt refers to the extra oxygen required after exercise to oxidise (combine with oxygen) lactic acid and remove it from cells</p>

Question 18

<p>What doesthe graph for rate of photosynthesis againsttemperature look like?</p>

Answer 18

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Question 19

<p>What doesthe graph for rate of photosynthesis against light look like?</p>

Answer 19

.

Question 20

<p>What doesthe graph for rate of photosynthesis against Carbon Dioxide look like?</p>

Answer 20

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Question 21

<p>What is the method to investigate theeffect on light intensity on Photosynthesis?</p>

Answer 21

<ol><li>Set up a test tube rack containing a boiling tube at a distance of 10 cm away from the light source</li><li>Fill the boiling tube with the sodium hydrogen carbonate solution</li><li>Put the piece of pondweed into the boiling tube with the cut end at the top. Gently push the pondweed down with the glass rod</li><li>Leave the boiling tube for 5 minutes</li><li>Start the stop watch and count the number of bubbles produced in one minute</li><li>Record the results in a table</li><li>Repeat the count twice more. Then use the data to calculate the mean number of bubbles per minute.</li><li>Repeat steps <strong>1‒7</strong> with the test tube rack and boiling tube at distances of 20 cm, 30 cm and 40 cm from the light source</li></ol>

Question 22

<p>How do you set up the equipment to investigate theeffect on light intensity on Photosynthesis?</p>

Answer 22

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Question 23

<p>State the word equation for photosynthesis</p>

Answer 23

<p>Carbon dioxide + water → glucose + oxygen</p>

Question 24

<p>What energy transfer occurs in photosynthesis?</p>

Answer 24

<p>Light energy to chemical energy</p>

Question 25

Describe how the inverse square law applies to light intensity and distance

Answer 25

The intensity of light is inversely proportional to the square of the distance from the light source. E.g. if you halve the distance, the light intensity will be 4 times greater

Question 26

What does the inverse square law mean in practice when considering how plants grow?

Answer 26

When the light is moved twice as far from the plant it will receive a quarter of the energy

Question 27

Why can’t a commercial grower of plants just increase all three limiting factors of PHS to maximum levels to obtain optimum growth?

Answer 27

Light, temperature and CO₂ all cost money to supply - a balance between expenditure and income must be struck for a profit to be made

Question 28

Name three ways glucose produced in photosynthesis is used in plants

Answer 28

• Used for respiration
• Converted into insoluble starch for storage
• Used to produce fat or oil for storage
• Used to produce cellulose which strengthens the cell wall
• Used to produce amino acids for protein synthesis

Question 29

What else, other than glucose, do plants need to produce proteins?

Answer 29

Nitrate ions

Question 30

Where are mineral ions absorbed from and through which plant organ?

Answer 30

From the soil, through the roots

Question 31

What is aerobic respiration and where does it occur in cells?

Answer 31

Respiration with oxygen, in the mitochondria

Question 32

What is anaerobic respiration and where does it occur in cells?

Answer 32

Respiration without oxygen, in the cytoplasm

Question 33

Is respiration an endo- or exothermic reaction?

Answer 33

Exothermic

Question 34

State the balanced symbol equation for aerobic respiration

Answer 34

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O

Question 35

How have humans used our understanding of anaerobic respiration in plant and yeast cells in manufacturing?/p>

Answer 35

Production of bread and alcoholic drinks

Question 36

Name three physical ways in which the human body reacts to an increased demand for energy

Answer 36

• Heart rate
• Breathing rate
• breathe volume

all increase

Question 37

Why do heart rate, breathing rate and breathe volume increase when the body needs more energy?

Answer 37

To increase the oxygenation of the blood and to supply the muscles with more oxygenated blood

Question 38

What does a build-up of lactic acid cause in muscles?

Answer 38

Muscle fatigue

Question 39

) Where is lactic acid converted back into glucose?

Answer 39

The liver

Question 40

How is lactic acid transported to the liver?

Answer 40

Via the blood

Question 41

What is produced when enzymes chemically break down carbohydrates?

Answer 41

Simple sugar monomers

Question 42

What is produced when enzymes chemically break down a lipid?

Answer 42

1 glycerol, 3 fatty acids

Question 43

What is produced when enzymes chemically break down proteins?

Answer 43

Amino acids

Question 44

What is metabolism?

Answer 44

The sum of all the reactions in a cell or the body