Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

AH Biology > Cells and proteins - 4 > Flashcards

Cells and proteins - 4 Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

where are the prosthetic group retinals found?

A

in bacteriorhodopsin molecules in membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what do retinals do?

A

absorb energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the energy absorbed by retinals used to do?

A

used to pump protons through the bacteriorhodopsin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

how is a proton gradient generated across the membrane?

A

by protons being pumped through the bacteriorhodopsin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

how is ATP generated?

A

by hydrogen ions diffusing back through membrane through ATP synthase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

how is chemical energy produced in plants?

A

converting light energy through photosynthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

in plants, what does the absorbed energy drive?

A

drives a flow of electrons along the electron transport chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are protons pumped across in plants?

A

across the thylakoid membrane into the stroma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is a retinal?

A

a prosthetic group which is covalently bound to a polypeptide called opsin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

where is opsin found?

A

embedded in membranes inside photoreceptor cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are the two classes of photoreceptor cells?

A

rods and cones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

describe a rod

A
  • contains rhodopsin

- adapted to detect low levels of light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

describe a cone

A
  • contains photopsin

- allows colour vision

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is rhodopsin connected to?

A

connected to hundreds of G-proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what amplifies a photon signal?

A

a cascade of proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what causes a conformational change in rhodopsin?

A

a photons of light being absorbed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what catalyses the breakdown of cGMP?

A

the hundreds of enzymes activated by hundreds of G-proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

when cGMP has been broken down into GMP what happens to the sodium channel?

A

sodium channel closes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what happens if there a sufficient build up of Na?

A

membrane becomes hyper polarised and a nerve impulse is generated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

why are cones less sensitive than rods?

A

there are fewer photoreceptor cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

in humans, how many photopsin does each cone cell have?

A

three photopsin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what does each photopsin have a maximal sensitivity to?

A

a specific wavelength of light - red, green or blue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

how are different photopsin made?

A

made by combining retinal with different forms of opsin

24
Q

what do cells use to communicate?

A
  • extra-cellular signalling molecules

- complimentary receptor proteins

25
Q

what are the main forms of coordination?

A

hormonal and nervous

26
Q

what is a target cell?

A

a cell that receives the signal

27
Q

how does a response come about in a cell?

A
  • receptor molecules on target cell binds with a specific signal molecule
  • changes conformation of receptor cells
  • changes behaviour of target cells
28
Q

can hydrophilic signalling molecules pass through the membrane?

A

no

29
Q

where are the receptors in hydrophilic signalling molecules?

A

receptors are at the membrane not inside the cell

30
Q

name two types of hydrophilic signalling molecules?

A
  • neurotransmitters

- peptide hormones (e.g insulin)

31
Q

what does hydrophilic signalling often involve?

A
  • cascades activated my G-proteins

- phosphorylation by kinase enzymes

32
Q

how does hydrophilic signalling molecules move across the membrane?

A

signal is transduced across the membrane

33
Q

what is insulin?

A

a peptide hormone produced by pancreas

34
Q

name the glucose transporter

A

GLUT-4

35
Q

what is GLUT-4 triggered by?

A

triggered by phosphorylation events

36
Q

what is diabetes mellitus?

A
  • deficiency in the effect of insulin

- loss of control of blood glucose levels

37
Q

what is type 1 diabetes?

A

failure to produce insulin

38
Q

what is type 2 diabetes?

A

loss of receptor function

39
Q

why can exercise help reduce the impact of type 2 diabetes?

A

triggers the recruitment of GLUT-4

40
Q

what is ADH?

A

peptide hormone

41
Q

when is ADH released?

A

released by pituitary gland in response to low blood water concentration

42
Q

what is the receptor protein for ADH?

A

G-protien

43
Q

where is G-protein found?

A

found in kidney nephron tubule (inside collecting ducts)

44
Q

what does ADH trigger?

A

triggers the recruitment of the channel protein aquaporin 2 (AQP2)

45
Q

what do aquaporins enable the cells to do?

A
  • provides an efficient route for water to move across membranes
  • allows control of water balance in terrestrial vertebrates
46
Q

what does a failure to produce ADH lead to?

A

diabetes insipidus

47
Q

can hydrophobic signalling molecules pass through the membrane?

A

yes the molecules can diffuse through the membrane

48
Q

what hormone is released from the thyroid?

A

thyroxine

49
Q

what is the role of the thyroxine?

A

to control the metabolism

50
Q

what a thyroid hormone binds to a receptor protein what happens to the metabolic rate?

A

metabolic rate increases

51
Q

when is the transcription of Na/K ATPase inhibited?

A

when the receptor protein is bound to DNA in the absence of thyroxine

52
Q

in the absence of thyroxine, what happens to the metabolic rate?

A

metabolic rate decreases

53
Q

what are some examples of steroids?

A
  • testosterone

- oestrogen

54
Q

when a steroid hormone passes through the membrane what acts as a transcription factor?

A

activated receptor proteins

55
Q

when a steroid hormone passes through the membrane what does it attach to and activate?

A

activates a receptor protein

AH Biology (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions