Respiration

Question 1

What is aerobic respiration?

Answer 1

An enzyme controlled process in living things
Takes place all the time - normal respiration - enough oxygen to allow respiration without oxygen debt
Digestive system, lungs and circulation work to provide cells with glucose needed for respiration

Question 2

What happens during aerobic respiration?

Answer 2

Glucose reacts with oxygen transferring energy to cells for everything that your body needs
Carbon dioxide and water are produced as waste products

Question 3

Why is it called aerobic respiration?

Answer 3

Uses oxygen from the air
Exothermic because it transfers energy to environment
More energy when new bonds formed in products than is taken in to break bonds in the reactants
Some energy is used for all the cells reactions, the rest is transferred to the environment making it slightly warmer.

Question 4

What is the equation for respiration?

Answer 4

Glucose + oxygen -> carbon dioxide + water + (energy transferred to the environment)
C6H12O6 + 6O2 -> 6CO2 + 6H2O + (energy transferred to the environment)

Question 5

Why do boys have higher energy needs than girls?

Answer 5

More muscle meaning more mitochondria
Boys are larger than girls
Boys have 11510kJ and girls have 8830kJ

Question 6

Where does most respiration take place?

Answer 6

Mitochondria
Tiny rod shaped organelles found in almost all animal, plant, algal and fungal cells
Folded inner membrane with large surface area for enzymes
A higher number of mitochondria indicates a more active cell

Question 7

What are the main needs for respiration?

Answer 7

1. Living cells need energy for basic functions of life, building larger molecules from smaller to make new material. Also breaking down larger molecules during digestion and within cells
   2 . Make muscles contract all the time requiring energy
2. Mammals and birds to maintain constant internal body temperature
3. Plants need energy to move mineral ions to root hair cells and also convert sugars, nitrates and other nutrients into amino acids and then into proteins

Question 8

What is muscle tissue made of?

Answer 8

Protein fibres that contract when energy is transferred from respiration
Contain many mitochondria to contract
Usually occur in big blocks that contract to cause movement
Relax to allow other muscles to work
Also store glucose as glycogen which is used in exercise

Question 9

What happens when you exercise?

Answer 9

Muscles using oxygen and glucose all the time
When exercising muscles contract harder and faster and need more glucose and oxygen for respiration
Muscles produce more carbon dioxide that needs removing

Question 10

What changes take place when you exercise?

Answer 10

1. Heart rate increase, arteries dilate increasing flow of oxygenated blood to muscles, increasing glucose and oxygen supply for respiration and increases rate of carbon dioxide removal from muscles
2. Breathing Rate increases and deeper breathing - more air into lungs each breath. Rate of oxygen into red blood cells increases and carried to muscles. Allows quicker removal of carbon dioxide from lungs
3. Glycogen in muscles converted to glucose to supply cells for increased respiration

Question 11

What is anaerobic respiration?

Answer 11

When you exercise hard your muscle cells become short of oxygen and even though you breathe hard and your heart rate increases your blood cannot supply oxygen to muscles fast enough.

When this happens energy from the breakdown of glucose can still be transferred to muscles by anaerobic respiration without oxygen.

Question 12

What happens with anaerobic respiration?

Answer 12

Not efficient because glucose molecules not completely broken down
End product is lactic acid rather than carbon dioxide and water
Incomplete breakdown means far less energy transferred

Question 13

What is the equation for anaerobic respiration

Answer 13

Glucose->lactic acid + (energy transferred to the environment)

Question 14

What happens when muscles fatigue

Answer 14

Muscles stop contracting efficiently

Caused by lactic acid build up - creating an oxygen debt

Question 15

Why do we breathe more deeply and more frequently after exercise

Answer 15

1The lactic acid can’t be breathed out like carbon dioxide
2 When exercise finishes the lactic acid has to be broken down to produce carbon dioxide and water and this needs oxygen
3 the amount of oxygen needed to do this is the oxygen debt

Question 16

What is the equation for oxygen debt repayment

Answer 16

Lactic acid + oxygen-> carbon dioxide + water

Question 17

What do plants form when they respire anaerobically

Anaerobic equation?

Answer 17

Glucose -> Ethanol + carbon dioxide

Question 18

What is anaerobic respiration on yeast cells called

Answer 18

Fermentation

Used in manufacture of bread and alcoholic drinks

Question 19

What is the equation for anaerobic respiration in other organisms

Answer 19

Glucose->ethanol + carbon dioxide(energy transferred to the environment)

Question 20

How does your body change during exercise as demand for energy increases

Answer 20

1 temperature increases- sweating
2 breathing quicker and deeper
3 heart rate increases
4 muscles get bigger
5 increased rate of respiration 
6 arteries to muscles dilate - get wider

Question 21

How do you test for carbon dioxide

Answer 21

Limewater goes cloudy with CO2
Doesn’t change with different levels of CO2
Shows how we breathe out CO2

Question 22

Where is glucose stored and how

Answer 22

Stored in liver as glycogen and released when exercising as glucose

Question 23

What are the the main difference between the amounts of gas we breathe in and breathe out

Answer 23

Breathe in more oxygen than breathe out carbon dioxide

Question 24

What are the 3 main organ systems involved in respiration

Answer 24

Respiratory system
Circulatory system
Digestive system

Question 25

Define cellular respiration

Answer 25

An exothermic reaction which occurs continuously in living cells

Question 26

What is the metabolism of an organ

Answer 26

The sum of the reactions that take place in the cell or body
Energy transferred by respiration in cells is used by the organism for the continual enzyme controlled processes that synthesise new molecules

Question 27

What are the common metabolic reactions

Answer 27

1 conversion of glucose to starch, glycogen and cellulose
2 formation of lipid molecules from one molecule of glycerol and 3 of fatty acids
3 use of glucose and nitrate ions to make amino acids and proteins
4 reactions of respiration
5 reactions of photosynthesis
6 break down of excess proteins in liver to form urea for excretion

Question 28

What is the role of the liver

Answer 28

1Reddish brown organ with differing functions
2 Liver cells grow and regenerate
3 many metabolic functions eg detoxifying ethanol from alcohol,
passing breakdown products into blood for excreting in urine via kidneys,
Breaking down worn out blood cells and storing iron for synthesis of blood cells

Question 29

How does the liver remove lactic acid

Answer 29

Blood from muscles transports lactic acid to liver
Converted to glucose
Oxygen debt repaid once broken down in aerobic respiration to make carbon dioxide
Glucose if not needed can be stored as glycogen in liver