unit 3 biology

Question 1

How does protein work in our body?

Answer 1

They catalyse reactions, they help bind cells to tissues, they can be antibodies which protect us from pathogens, they transport material, they can carry chemical messenges(hormone), they control the activity of genes.

Question 2

What is a dipeptide?

Answer 2

When only two amino acids join.

Question 3

What is it called when less than 50 amino acids join?

Answer 3

Oligopeptides.

Question 4

What is it called when more than 50 amino acids join together?

Answer 4

polypeptides.

Question 5

How does an amino acid join with another amino acid to form protein?

Answer 5

By joining the hydroxides from one amino acid with the hydrogen from the other amino acid.

Question 6

What is the bond called when two amino acids join and what is the reaction called?

Answer 6

Peptide bond and it is called condensation reaction.

Question 7

What determines the function of different amino acids?

Answer 7

The R group

Question 8

What are the four steps in when the enzyme breaks down the substrate?

Answer 8

1. The substrate is bonded to the specific enzyme.
2. Then it forms a enzyme-substrate complex. 3. The binding of the substrate leads to stress being put on the products. 4. The products are released and seperated from the enzyme for the enzyme to bind to other substrates.

Question 9

What is activation energy?

Answer 9

The minimum energy needed for particles to start moving or reacting?

Question 10

What do enzymes do to activation energy?

Answer 10

Lower the activation energy so the particles can get moving and start reacting

Question 11

Why would an enzyme become denatured when the temperature is above a temperature?

Answer 11

Because the active site has become denatured and changed shape which means it cannot bind to the substrate and the enzyme can no longer do its job.

Question 12

What are the four factors that affect enzyme activity and how does it affect it?

Answer 12

Temperature-As temperature increases, it increases the kinetic energy then the enzyme activity increases until it reaches the optimum temp the enzyme works at, the enzyme then works the best. Then after the active site then becomes denature because the temperature goes above the optimum temperature and so the active site does not have the right shape and so the enzyme will not work.
PH- The increasing ph increases the reaction but then when it gets to an optimum the active site will become denatured as the hydrogen bonds in the enzyme are sensitive to the hydrogen ions in the ph.
Substrate concentration- When the substrate concentration increases, then the enzyme reaction will increase but then when the substrates increase even more then the reaction will stay the same because the enzymes are busy.

Question 13

What is the risk,precaution and emergency for broken glass in the risk assessment for the enzyme practical?

Answer 13

The risk is cuts. The precaution is keeping glassware from the edge of the desk. The emergency is to not remove glass from cuts and seek medical assistance.

Question 14

What is the risk,precaution and emergency for boiling water?

Answer 14

The risk is scalding,precaution is handle boiling water with care;use tongs to transfer boiling tubes;wear safety goggles.

Question 15

What is the emergency for boiling water?

Answer 15

Apply the affected area under cold water and seek medical asistance.

Question 16

What is the risk,precaution and emergency for amylase solution?

Answer 16

The risk for amylase solution is that it irritates eyes and irritates skin. The precaution for eyes is to avoid contact with eyes and the precaution for the skin is to wear gloves. The emergency for the eyes is that flood eyes with tap water and seek medical assistance. And the emergency for irritation for skin is remove contaminated clothing and run the affected area under cold water and seek medical assistance.

Question 17

What is the risk,precaution and emergency for iodine solution?

Answer 17

The risk is irritation to eyes and precaution is avoid contact with eyes and wear safety goggles and the emergency is flood eyes with tap water and seek medical assistance.

Question 18

What do plants need to grow and be healthy?

Answer 18

Light,water,nutrients, carbon dioxide, space and a suitable temperature.

Question 19

What do plants compete for?

Answer 19

Light, water,carbon dioxide,space and nutrients.

Question 20

What factors affect the rate of plant growth?

Answer 20

Ph of soil-some plants require acidic conditions some require alkaline conditions
light intensity,
How much air in the soil, Temperature, moisture and Ions.

Question 21

What is meant by distribution of plants?

Answer 21

Location and population

Question 22

What is hypothesis for light intensity on rate of photosynthesis?

Answer 22

As light intensity increases so does the number of bubbles increase.

Question 23

What is the equipment used for the light investigation on plants?

Answer 23

Use a lamp,test tube,plants,sodium carbonate,rack of test tube and Ruler.

Question 24

Method for light investigation on plant?

Answer 24

First add a plant in a test tube. Add water to the test tube. Add sodium carbonate in the plant. Make sure lamp is on. Then add the first test tube at 10cm close to the lamp. Measure the bubbles of oxygen. Then repeat this till 50cm from the lamp.

Question 25

What are controlled variables,independant and dependant variable for the plant?

Answer 25

Controlled variable is the plant size and volume of water. Independant variable- Distance of test tube
Dependant variable- Number of bubbles produced.

Question 26

What is the equipment used for investigating temperature on amylase activity?

Answer 26

1 percent of starch solution, 1%of amylase solution,iodine solution, 5cm cube syringe,10 boiling tubes,6 pippettes,spotting tiles, water baths:20,30,40,50 and 60 degrees celcius,stopwatch and permanent marker pen.

Question 27

What is the method for investigating temperature activity on amylase enzyme?

Answer 27

Set up five water baths:20,30,40,50 and 60 degrees celcius.
2. Using a pipette,place a single drop of iodine solution into each well of a spotting tile.
3. Set up five boiling tubes containing 2cm 1% starch solution and five boiling tubes containing 2cm 1%amylose solution.
4. Label each pair of boiling tubes with a temperature and place in the corresponding water baths for 10 minutes to equilibrate.
5. Remove the boiling tube containing 1% starch from the 20 degrees water bath and using a 5cm cube syringe,add 2cm cube 1%starch into the 20 degrees 1% amylase solution. Start the stopwatch
6. Mix using a pipette. After 30 seconds, remove a sample of the reaction mixture using a pipette and place a drop of it onto the iodine in the first well. Record observations.
7. Repeat this every 30 seconds until no further colour change is observed(the iodine remains yellow-brown). Note the time at which no colour change occurs.
8. Repeat steps 5 to 8 for the four other temperatures.
9. Repeat the method a further two times to obtain three repeats for each temperature.

Question 28

What is the independant variable,dependant variable and controlled variable for effect of temperature on amylase enzyme?

Answer 28

Independant variable is the temperature,dependant variable=time taken for no further colour change. Controlled variable= volume of iodine in each well,volume of 1% starch solution and concentration of starch solution and amylose solution.
TIme at which samples of the reaction mixture are remove.