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Structure and functions in living organisms > Biological molecules > Flashcards

Biological molecules Flashcards

1
Q

Explain why no droplets are seen after bile and lipase solution is added to the oil and water mixture.

A
  • Emulsification
  • Smaller drops
  • optimum pH
  • Digestion
  • Lipase is an enzyme
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2
Q

Explain how the structure of villi is adapted to absorb glucose

A
  • Large SA
  • Diffusion
  • Active transport
  • Once cell thick
  • Movement of blood
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3
Q

The results for the spotting tile at 40 degrees Celsius would be different from the trial carried out at 20 degrees Celsius

Describe how the appearance of the results will be different

A
  • Fewer wells with a blue-black color
  • Starch digested quicker
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4
Q

Give three ways in which villi are adapted to absorb small food molecules

A
  • Large SA
  • thin
  • Permeable
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5
Q

Explain the difference in the appearance of the results

A
  • Enzymes work faster at 40 degrees Celsius
  • There is more KE
  • More collisions
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6
Q

Explain what happens in a leaf when it is destarched

A
  • Starch is removed and is converted into glucose for respiration/energy
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7
Q

Describe how the green pigment in leaf cells is removed safely before testing a leaf for the presence of starch

A
  • Boil ethanol with the help of a water bath
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8
Q

Describe two chemical tests he should use to identify each carbohydrate

A
  • Iodine
  • If blue-black = starch is present
  • Use water bath
  • Red–> Orange–> Yellow–>Green = glucose is present
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9
Q

A student carried out some food tests on two samples of food, A and B. The table shows the results.

The student concluded that both samples of food contained carbohydrates

Do you agree with this conclusion?

Give reasons for your answer.

A

(Yes)

A is starch

B is glucose

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10
Q

On a hot day, there is less water in urine.

Explain how the kidney is able to reduce the water content of urine produced on a hot day.

A
  • Reabsorption of water
  • increase permeability
  • collecting duct
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11
Q

Explain why there is no glucose in the urine

A
  • absorbed back into the blood
  • active transport
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12
Q

Explain why there are no plasma proteins in the urine.

A
  • Protein molecules are too large
  • Leave capillaries
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13
Q

Suggest why the saliva released onto the lion’s mouth does not contain amylase

A
  • Lion eats protein
  • Amylase cannot digest protein
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14
Q

Explain how tearing the meat into smaller pieces help digestion in the stomach

A
  • Protease
  • Increased SA:V
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15
Q

Zebras also try to avoid being caught by lions. It was thought that the striped coat of zebras helps to camouflage them.
A new theory suggests the striped coat evolved because it reduces the number of biting flies that feed on zebra blood.
Use your knowledge of natural selection to explain how a striped coat that reduces the number of flies feeding on zebra blood may have evolved.

A
  • variety
  • mutation
  • survival
  • reproduction
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16
Q

Gazelles cannot maintain their top speed for a long time because a change in the type of respiration takes place in their muscle cells. Explain how this change in respiration stops gazelles from running at a top speed for a long time.

A
  • anaerobic (respiration)
  • less oxygen
  • low pH
  • denatures enzymes
17
Q

Describe how you could test for the presence of glucose in a substance

A
  • Benedicts solution
  • Use water bath
  • Red–> Orange–> Yellow–>Green = glucose is present
18
Q

Name the mineral in meat that is needed to make hemoglobin.

19
Q

Wasps defend themselves from predators by using a sting. This means that predators avoid attacking wasps.
Ash borers look very similar to wasps. Use your knowledge of natural selection to explain why ash borers have evolved
to look like wasps.

A
  • Mutation
  • To not get eaten
  • Pass on gene(s)
  • Survival
20
Q

Describe how magnesium ions are used to help trees to grow.

A
  • Chlorophyll
  • absorb light
21
Q

Name and describe the process used by root cells to absorb mineral ions.

A
  • active transport as it goes from an area of low conc. to an area of high conc.
22
Q

Explain the change in the rate of urease activity from 10 degrees to 36 degrees

A
  • More KE
  • More collisions
23
Q

Explain the change in the rate of urease activity from 36 degrees to 50 degrees

A
  • It becomes denatures
  • Active site changes shape
  • Substrate no longer fits
24
Q

how do nitrate ions help plants grow?

A

Amino acids

25
Use your knowledge of enzymes to explain why blood is slow to clot at 45 degrees
- denatured -Active site changes shape
26
plain why blood takes longer to clot at 20 degrees than it does at 30 degrees
- further away from the optimum temperature - Low KE - Fewer collisions
27
The student keeps the Petri dish at 20 °C to control the temperature in order to make a valid comparison between each pH. Name three other variables that the student needs to control.
- Vol. of amylase - Time - Conc. of amylase
28
Explain why there is a clear zone around some of the wells containing amylase
- digestion - no starch
29
Explain why the clear zones have a range of different diameters. The diameters of the wells do not change during the experiment.
- enzymes denatured at pH13 - optimum pH is pH7
30
Explain how the student could use these solutions to estimate the concentration of sugar in the four fruit juices.
- Use the same volume of sugar solution - Use the same volume of benedicts - heating at the same time for the same temperature - Comparing sugar with the fruit juices
31
Sodium carbonate solution is an alkali that turns the indicator pink in step 3. Explain why the indicator changes color in step 7.
- Break down of lipids by the lipase into fatty acids and glycerol. - With the acid production, the pH will decrease.
32
Explain the effect of temperature on the time taken for the indicator to change color.
- At lower temperatures, it takes longer - At lower temperatures, there is less KE which means there are fewer collisions - At higher temperatures, the enzyme denatures. The active site changes shape, and the substrate can no longer fit.
33
Using the photograph, explain how many minutes it took for the reaction to be completed at 20 °C
- 6 minutes - because the iodine stays yellow-brown it does not turn into blue-black which means there is no starch present as it is broken down by the amylase.
34
The results for the spotting tile at 40 °C would be different from the trial carried out at 20 °C. Describe how the appearance of the results will be different.
- Fewer wells with blue-black color which means there is no starch present because the starch is digested quicker.
35
Explain the difference in appearance of the results.
- The enzyme works faster at 40 °C. - There is more KE of particles and more successful enzyme-substrate collisions.

Structure and functions in living organisms (11 decks)

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