UNIT 3- MISS LIDDELL'S WORK

Enzymes:

1. what is an enzyme?

2. what is the collision theory?

1. Protein molecules which act as biological catalysts. They speed up reactions.

2. For a reaction to occur, particles must collide with the minimal energy needed to react. Enzymes lower the activation energy of a reaction + increases rate of reaction.

Enzymes: Factors affecting enzymes

1. Temp

2. pH

3. Substrate and enzyme concentration

4. inhibitors

1. Enzymes have an optimum temp, at low temps they work more slowly + at high temps they can become denatured.

2. Enzymes have an optimum pH, at pH that is significantly higher or lower than optimum, enzyme becomes denatured.

3. The more substrate or enzyme there is, the faster the reaction will occur until either the sub of enz conc becomes the limiting factor.

4. As the conc of inhibitor increases, rate of reaction decreases, as the sub cannot access the active site + no more ESC formed. This can be temporary or permanent.

Enzymes:

what is the primary, secondary and tertiary structure?

1. primary

2. secondary

3. tertiary

1. The sequence of amino acids in a polypeptide chain

2. Local folding of protein chain into α-helices and β-pleated sheets, formed by hydrogen bonds between amino acids in the chain.

3. Hydrogen bonds, ionic bonds, disulphide bonds + hydrophobic interactions

Enzymes: Analysing graphs

• As temp increases up to 40°C(optimum temp), enzyme activity increases

• Higher temp leads to more KE, more collisions and lower activation energy needed

• Above 40°C, enzyme activity decreases as high temps break hydrogen bonds + enzyme denatures

• Active site changes shape + sub no longer fits

• By 65°C, enzyme activity drops to zero as it is fully denatured

Enzymes: Analysing graphs

• At 30°C, enzyme activity stays at 100% which is at stable, optimal conditions.

• At 50°C, enzymes start to denature over time and activity gradually decreases

• Bonds break and tertiary structure disrupted, so fewer enz-sub complexes form

• At 60°C rapid denaturation occurs and by 30mins at 60°C, all enzymes are denatured.

Plants:

What is an..

1. Ecosystem

2. Species

3. Population

4. Habitat

5. Community

6. Niche

7. Biodiversity

1. E- Interactions between living organisms and non-living components

2. S- A group of organisms that can interbreed to produce fertile offspring

3. P- All organisms of one species living in the same place at the same time + can breed together

4. H- The place where an organisms lives

5. C- All populations of different species living + interacting in the same place

6. N- The role a species plays in its ecosystem

7. B- The number + variety of living organisms in an area, world, ecosystem or habitat.

Plants: