METABOLISM

Question 1

Metabolism

Answer 1

All the chemical reactions that take place in the cells.

Question 2

Catabolism

Answer 2

The process where large molecules are broken down into smaller molecules and energy.

Examples: Digestion and Deamination

Question 3

Anabolism

Answer 3

The process when small molecules are built up into larger molecules with the use of energy.

Examples: all the synthesis

Question 4

Nutrients

Answer 4

Nutrients are substances that can help the body in growth, repair and maintenance.

Question 5

6 main types of nutreients

Answer 5

1. carbohydrates
2. proteins
3. lipids
4. water
5. vitamins
6. minerals

Question 6

Organic nutrients/ compounds

Answer 6

Organic compounds are compounds that have a carbon chain.

They include elements such as carbon, hydrogen atoms and may include, oxygen, sulfur and nitrogen.

Question 7

Carbohydrates (Organic)

Answer 7

• The main source of energy for cells. Contain, hydrogen, carbon and oxygen atoms.
• They are broken down into simple sugars such as glucose, and are used in cellular respiration to release energy.

Question 8

Lipid (Organic)

Answer 8

• lipids include fat and oil and are also an important energy source.
• They are broken down into fatty acids and glycerol
• glycerol can enter cellular respiration and can be broken down to release energy.
• other examples of lipids include phospholipids and steroids

Question 9

Proteins (Organic)

Answer 9

• Organic compounds made up of many amino acids. They contain O, H, Ca, N, S, F
• Proteins are enzymes and can be used as a source of energy BUT only if the source of carbohydrates and lipids is inadequate.
• An amino acid consists of both an amino group and a carboxylic group.

Question 10

Inorganic compounds

Answer 10

Compounds that are not based on a carbon chain.

Question 11

Water (Inorganic)

Answer 11

Water is an important organic substance as it is the fluid that other substances are dissolved in.

some chemical reactions occur in water.

Question 12

Minerals (Inorganic)

Answer 12

Minerals are important because they may be apart of enzymes.

May act like a co-factor for enzymes.

May be apart of ATP that are involved in metabolism

Question 13

Vitamins (ogranic)

Answer 13

Act as co-enzymes for the many chemical reactions.

Are organic as they consist of a carbon chain

Question 14

Conditions met for chemical reactions to occur.

Answer 14

The reacting particles need to collide with enough energy to break the bonds.

Particles must also collide so that the correct atoms come into contact with one another.

Question 15

Activation energy

Answer 15

Minimum amount of energy needed to start a chemical reaction.

Question 16

Temperature and activation energy

Answer 16

At any give temperature, a certain proportion of particles will have enough energy to satisfy the activation energy.

The proportion will increase, as the temperature increases.

Question 17

Catalysts

Answer 17

Chemicals that lower the activation energy, and increase the rate of reactions. They are not consumed in the reaction making them more effective.

Catalysts are proteins called enzymes.

without enzymes, the reactions would be too slow

Question 18

Substrate

Answer 18

The molecules on which an enzyme acts in.

Question 19

Active site

Answer 19

The part of an enzyme molecule that combines with the substrate is called the active site.

Question 20

Enzyme substrate complex

Answer 20

Occurs when an enzyme and substrate combines.

There are 2 models:
1. The lock and key model
2. Induced fit model

Question 21

The lock and key model

Answer 21

The shape of the enzyme is always complementary to the shape of the substrate.

Question 22

The induced fit model

Answer 22

When the enzyme and substrate join, they form weak bonds that cause the shape of the enzyme to change, creating complementary shapes.

Question 23

Factors affecting enzymes activity

Answer 23

1. The higher concentration of enzymes
2. Increase substrate concentration also increases the rate of the reaction: More substrate molecules come in contact with enzymes. However increasing substrate beyond conc will cease effect.
3. The product of the reaction must be continually removed: Slow rate of reaction, as it is more difficult for substrates to meet enzymes
4. the temperature influences enzyme activity: 40 - 45 deg enzymes will denature
5. enzymes are very sensitive to the PH of the medium in which a reaction is taking place.

Question 24

Co-factors

Answer 24

Ions and non-proteins that are present before enzymes catalyse a reaction.

they can also change the shape of the active site.

without a cofactor enzymes cannot function

Question 25

Co- enzymes

Answer 25

some co-factors that are organic molecules. Many vitamins

Question 26

Enzyme inhibitors

Answer 26

Substances that slow or even stop the enzyme's activity. - They can block the active site or change the shape of it, not allowing the substrate to come in contact with the enzyme. Many drugs are an example

Question 27

Cellular respiration

Answer 27

The process of which cells break down organic molecules to produce energy in the form of ATP for the cells activities. Most important metabolic processes in any cell can release energy from, glucose, amino acids, fatty acids, and glycerol

Question 28

Cells activities

Answer 28

- Movement of the cell - Movement of material across the cell membrane - uptake of material from surrounding - production and secretion of chemicals

Question 29

Cellular respiration equation

Answer 29

glucose + oxygen = carbon-dioxide+ water + energy (ATP and heat)

Question 30

Energy from Cellular respiration (HEAT)

Answer 30

- In the complete breakdown of glucose, about 60% of the available energy is released as heat. - Heat is important to keep body temperatures constant as they are continually lost to the environment.

Question 31

Energy from Cellular respiration (ATP)

Answer 31

- The remaining energy (40%) is used to form a compound called adenosine triphosphate (ATP) - adenosine - which is make up of the nucleic acid bases adenine and the ribose sugar. - thee phosphate groups. - ATP is formed when an inorganic phosphate group is attached to ADP. - Some energy is form cellular respiration is stored in here. - This bond can easily be broken, allowing energy to be released when needed. - As energy is released (can be re-used) ADP is formed gain.

Question 32

Glycolysis

Answer 32

The first phase in breaking down glucose to 2 pyruvate molecules, doesn't require oxygen.

Question 33

Anaerobic respiration

Answer 33

- Respiration with the lack of oxygen. - The process of glycolysis and conversion of pyruvate to lactic acid is available in the cytosol. - one molecule of glucose is enough to convert 2 molecules from ADP to ATP, with the absence of oxygen. - Anaerobic respiration is very important for vigorous activity, when the respiratory and circulatory systems are unable to supply muscle cells with enough oxygen to meet all the energy demands for the contracting muscles.

Question 34

Lactic acid in anaerobic respiration

Answer 34

- lactic acids may cause muscle pain, due to anaerobic respiration producing extra energy. - lactic acids are taken by the blood to the liver, where it can recombine with oxygen to form glucose and eventually glycogen. - this process needs oxygen.

Question 35

Oxygen debt

Answer 35

After running, runners breathe heavily for some time because the oxygen debt must be repaid by converting lactic acid into glucose.

Question 36

Recovery oxygen

Answer 36

The extra oxygen required after exercise.

Question 37

Aerobic respiration

Answer 37

- Respiration requiring oxygen -complete breakdown of glucose to carbon-dioxide and water, requires oxygen. - Process occurs in the inner membrane of the mitochondria, the folds of the internal membrane provides a large surface area in which these reactions can take place.

Question 38

aerobic respiration steps

Answer 38

1. For pyruvate to enter the mitochondria, carbon-dioxide is removed from the pyruvate and it forms acetyl co-enzyme A. (NO ATP PRODUCED) 2. The acetyl COA, enters the citric acid cycle (Krebs cycle). Here the carbon atoms in the acetyl COA are released in carbon-dioxide. For every acetyl COA that enters the cycle, one molecule of ATP is also produced. This means that 2 ATP molecules are produced per glucose molecule. 3. The final step is known as the electron transport chain, the only stage that uses oxygen. here the electrons are passes between molecules, finally resulting in oxygen molecules forming water. roughly around 26-34 molecules are produced during this process. MAX 38 ATP molecules from 1 molecule of glucose