2014 Unit 1 Flashcards

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1
Q

Describe how phospholipids are arranged in a plasma membrane

A
  • Bilayer
  • Hydrophobic/ fatty acid/ lipid tails to inside
  • Polar/ phosphate group/ hydrophilic head to outside
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2
Q

Cells that secrete enzymes contain a lot of rough endoplasmic reticulum (RER) and a
large Golgi apparatus.

Describe how the RER is involved in the production of enzymes.

A
  • Rough Endoplasmic Reticulum has ribosomes

* To make a protein (which is an enzyme)

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3
Q

Describe how the Golgi apparatus is involved in the secretion of enzymes

A
  • Golgi Apparatus modifies proteins
  • Golgi Apparatus packages/ puts into Golgi vesicles
  • Transport to cell surface/ vacuole
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4
Q

Give two risk factors associated with coronary heart disease.

A
  • Smoking
  • High (blood) cholesterol
  • High blood pressure
  • Obesity
  • Gender
  • Age
  • Genes
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5
Q

During a myocardial infarction, areas of heart muscle begin to die.
Explain why.

A
  • Reduced blood flow in coronary artery/ coronary artery blocked
  • Less/no oxygen
  • Respiration drops/stops (so cells begin to die)
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6
Q

Describe how bacteria are destroyed by phagocytes.

A
  • Phagocyte engulfs to form phagosome
  • Lysosome empties contents into phagosome
  • Releasing enzymes that digest/hydrolyse bacteria
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7
Q

Give two structures a bacterial cell may have that a white blood cell does not have

A
  • Cell wall
  • Capsule layer
  • Circular DNA
  • DNA without histones
  • Flagellum
  • Plasmid
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8
Q

Give two structures in the epithelial cells in the small intestine that are adaptations that make it possible for the rapid absorption of glucose

A
  • Microvilli
  • Mitochondria
  • Vesicles
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9
Q

Microvilli/Mitochondria/ Vesicles, explain how it is an adaptation to make possible the rapid absorption of glucose in small intestine.

A
  • Microvilli increase surface area for transport proteins/ for diffusion)
  • Mitochondria to supply ATP/ energy for active transport/ co-transport
  • Vesicles to bring carrier proteins to membrane
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10
Q

The absorption of glucose into the cell leads to the movement of water into the cell.
Explain how

A
  • Lowers water potential of the cell

* Water moves in by osmosis

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11
Q

Explain how the pressure in the dog’s ventricle is

related to blood flow into the aorta.

A
  • Ventricle pressure rises then blood starts to flow into aorta
  • Because pressure above that in aorta causes semi-lunar valve to open/ pressure below that in aorta causes semi-lunar valve to be shut
  • Ventricle pressure starts to fall so blood flow falls
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12
Q

Explain how the pressure in the dog’s ventricle is

related to the thickness of the ventricle wall

A
  • Thickness of wall increases because ventricle wall contracts
  • Contraction causes an increase in pressure
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13
Q

Use your knowledge of digestion to suggest how the addition of the inhibitor could lead
to a lower blood glucose concentration.

A
  • Fewer enzyme-substrate complexes formed
  • (With inhibitor) less/no starch digest to maltose
  • So less glucose from maltose
  • So less absorption of glucose
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14
Q

People given whole-cell vaccines were more likely to develop harmful side effects than
the people given the vaccines containing parts of the bacterial cells. Explain why

A

Whole Cell Vaccines
• Some might still be alive/active
• If so bacteria could reproduce
• Bacteria or toxins attacking/ killing person’s cells

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15
Q

People given whole-cell vaccines produced a greater range of antibodies against the
bacterium than the people given the vaccines containing parts of the bacterial cells

A

Whole Cell Vaccines
• Contains many different/ greater range of antigens
• Each antigen causes its own immune response

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16
Q

In humans, the enzyme maltase breaks down maltose to glucose.This takes place at normal body temperature.
Explain why maltase:
• only breaks down maltose
• allows this reaction to take place at normal body temperature.

A
  • Tertiary structure means active site complementary to substrate
  • Induced fit- When a substrate molecule collides with an enzyme, if its composition is specifically correct, the shape of the enzyme’s active site will change so that the substrate fits into it
  • Enzyme is a catalyst
  • Lowers activation energy
  • By forming enzyme-complex
17
Q

Scientists have investigated the effects of competitive and non-competitive inhibitors of
the enzyme maltase.
Describe competitive and non-competitive inhibition of an enzyme

A

• Inhibitors prevent formation of enzyme-substrate complexes
Competitive Inhibition
• Inhibitor similar shape to substrate
• Binds to active site of enzymes
• Inhibition can be overcome by more substrate
Non-competitive Inhibition
• Inhibitors binds to site on enzyme other than active site
• Changes shape of active site
• Cannot be overcome by adding more substrate