Brainscape's Knowledge GenomeTM

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


See full index

Biochemistry > Test 3 - Bartling > Flashcards

Test 3 - Bartling Flashcards

1
Q

Cellular signal transduction cassettes detect, amplify, and integrate external signals comprised of:

A
  1. Specific cell surface membrane receptors
  2. Effector signaling elements
  3. Regulatory proteins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Six steps of signaling

A
  1. Synthesis of the signaling molecule (ligand)
  2. Release of the signaling molecule (ligand)
  3. Transport of signaling molecule to target cell
  4. Binding of the ligand by a specific receptor protein and CHANGE in conformation
  5. Change in cellular metabolism, function, or development - cellular response
  6. Removal of ligand, terminating cellular response
  7. Degradation of ligand
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Define hormones

A

Chemical messengers made by endocrine cells and secreted into the blood

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

T/F: Hormones affect gene expression and protein synthesis

A

True

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

Autocrine hormones

A

Act on the same cell that they were secreted from

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

Paracrine hormones

A

Act on other cells

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

Types of hormones

A
  1. Steroids
  2. Amine (amino acid derived)
  3. Peptide (lumped with polypeptides)
  4. Polypeptides
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

3 Cholesterol Precursors:

A
  1. Corticosteroids
  2. Androgens
  3. Estrogens
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What do steroids immediately do?

A

Diffuse out of endocrine cells into the blood

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

Are steroid hormones lipid soluble?

A

Yes. They can cross cell membranes.

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

Where are the steroid hormone receptors?

A

Intracellular (cytoplasmic) receptors are located inside target cells

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

Steroid hormones have a _____ (longer/slower) acting, _____ (longer/slower) half-life than peptide hormones.

A

Slower Acting

Longer half-life

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

How do steroid hormones lead to signal cascades?

A
  1. Hormone diffuses into cell
  2. Activated receptor hormone complex alters gene expression
  3. New mRNA directs synthesis of certain proteins to ribosomes
  4. New proteins alter cell activity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are Amine hormones derived from?

A

Tryptophan and Tyrosine

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

Where are amine hormones stored until they’re secreted?

A

In endocrine cells

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

Where are amine hormone receptors located?

A

Can be located on the cell surface or intracellular

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

Do polypeptide hormones immediately enter the blood?

A

No. They can be stored in endocrine cell vesicles

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

Polypeptide hormones are ___ soluble

A

Water

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

Do polypeptide hormones readily pass through the cell membrane?

A

No

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

What are polypeptide hormones also called?

A

First messengers - they bind to external receptors

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

Intracellular effects are mediated by

A

Second messengers

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

Second messengers are ____ (low/high) weight signaling molecules such as:

A

Low molecular weight

Cyclic adenosine monophosphate (cAMP) or Calcium

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

G-protein coupled receptors are ___ ___ proteins

A

Integral membrane proteins (extracellular N-terminus)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

G-protein coupled receptors have ___ (#) transmembrane-spanning alpha-helices (ligand binds to pocket)

A

7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

G-protein coupled receptors have ___ (#) extracellular and intracellular loops.

A

3 - the third intracellular loop recruits G-proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

G-protein coupled receptors have an intracellular ___-____ ____ ____

A

C-terminal tail membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Do G-protein coupled receptors have intrinsic catalytic domains?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

G-protein (guanine nucleotide-binding) activates:

A

Adenylyl cyclases (converts ATP to cAMP). It also activates protein kinases in the cytosol (signal cascade)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Phosphodiesterase inactivates

A

cAMP (turns off cell response)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Specificity of a G-protein is conferred by the ___-____, which contains the GTP-binding site and an ___ ____ activity

A

Conferred by the alpha-subunit which contains the GTP-binding site and an intrinsic GTPase activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Adenylyl cyclase is activated by:

A

The action of the alpha-subunit of the G-protein (Gs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

With adenylyl cyclase, each molecule of bound hormone can stimulate many Gs alpha-subunits that amplifies the:

A

Original hormone signal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

2 Bacterial toxins that target G-proteins:

A
  1. Cholera toxin

2. Pertussis toxin (whooping cough)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

With Cholera toxin, what does ADP do?

A

Ribosylates Gs alpha subunit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

With Cholera toxin: An increase in ____ within the intestinal epithelial cells leads to _____ of Cl- channels and efflux of ___ and ___ (____ ____).

A

With Cholera toxin: An increase in cAMP within the intestinal epithelial cells leads to phosphorylation of Cl- channels and efflux of electrolytes and water (severe diarrhea).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

With Pertussis toxin, what does ADP do?

A

Ribosylates Gs alpha subunit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

With Pertussin toxin: The enhanced ____ levels inhibit ___ functions

A

Enhanced cAMP levels inhibit neutrophil

38
Q

Do Tyrosine kinase-linked receptors have intrinsic enzymatic activity?

A

No

39
Q

With Tyrosine kinase-linked receptors: Ligand binding forms a ____ that activates ___ ____ to phosphorylate downstream targets (signal cascade)

A

Ligand binding forms a dimer that activates tyrosine kinases

40
Q

Intrinsic enzymatic activity receptors are ____-triggered protein _____

A

Ligand-triggered protein kinases

41
Q

Intrinsic enzymatic activity receptors are similar to:

A

Tyrosine-linked receptors (form dimers upon ligand binding)

42
Q

With Intrinsic enzymatic activity receptors: Ligand/receptor complex directly acts as a ___ ___

A

Tyrosine kinase (phosphorylates other kinases)

43
Q

With Intrinsic enzymatic activity receptors: Phosphorylation activates _____

A

Other protein kinases

44
Q

In ion-channel receptors, ___ binding changes confirmation of the receptor

A

Ligand

45
Q

Ligand binding in ion-channel receptors allows for:

A

Specific ions (sodium, potassium) to flow through the channel.

46
Q

___ ___ prevents the release of acetylcholine neurotransmitter and cleaves proteins involved in docking of neurotransmitter vesicles

A

Botulinum toxin

47
Q

Cells maintain steep intracellular (____)/extracellular (___) Calcium concentration gradient that enables rapid changes in Calcium concentration via __ ___

A

100nM

1mM

Hormone ligation

48
Q

Calcium binds to ___ protein, inducing conformational change

A

Calmodulin

49
Q

Calmodulin protein is __ __ __ joined by a long __ __

A

2 globular domains

long alpha helix

50
Q

Calcium/calmodulin complex binds to and modifies __ __ that initiate __ __

A

Target proteins (kinases)

Signal cascade

51
Q

________ is the second messenger responsible for calcium mobilization

A

Phosphatidylinositol 4,5-bisphosphate (PIP2)

52
Q

PIP2 is hydrolyzed by a __ __ __ __ (PLC) to generate 2 second messengers

A

PIP2 Specific Phospholipase C

53
Q

The 2 second messengers generates by hydrolyzed PIP2

A

Inositol triphosphate (IP3)

Diacylglycerol (DAG)

54
Q

IP3 is __ soluble and it mobilizes ___

A

Water

Calcium

55
Q

DAG is anchored in the plasma membrane due to:

A

Hydrophobic fatty acid side chains

56
Q

DAG activates:

A

Key protein kinase C (PKC) family

57
Q

_____ can be hydrolyzed to other phospholipases to produce other lipid second messengers

A

Phosphatidylcholine

58
Q

Second messengers produced by hydrolyzed Phosphatidylcholine

A
  1. Different species of DAG
  2. Phosphatidic acid
  3. Arachidonic acid
59
Q

Species of DAG are generated by

A

PLC

60
Q

Phosphatidic acid is generated by

A

PLD

61
Q

Arachidonic acid is generated by

A

PLA2

62
Q

__ __ and __ are key inflammatory and pain mediators

A

Arachidonic acid and prostaglandins

63
Q

Arachidonic acid and prostaglandins are precursors of

A

Eicosanoids

64
Q

4 Eicosanoids

A
  1. Prostaglandins
  2. Prostacyclins
  3. Thromboxanes
  4. Leukotrienes
65
Q

Eicosanoids act like ___ and signal via:

A

Hormones

G-protein coupled receptors

66
Q

Arachidonic acid and prostaglandins modulate

A
  1. Smooth muscle contraction
  2. Platelet aggregation
  3. Gastric acid secretion
  4. Salt and water balance
67
Q

Arachidonic acid conversion to prostaglandins involves a ___ ___

A

Cyclooxygenase isoform

68
Q

2 cyclooxygenase isoforms

A

COX-1 (constitutive) and COX-2 (response to inflammatory mediators)

69
Q

COX-1 and COX-2 roles:

A
  1. Stimulate inflammation
  2. Regulate blood flow to organs such as the kidney
  3. Control ion transport across membranes
  4. Modulate synaptic transmission
  5. Induce sleep
70
Q

Example of cyclooxygenase inhibitors

A

Nonsteriodal anti-inflammatory drugs (NSAIDs)

Aspirin and Ibuprofen

71
Q

Role of cyclooxygenase inhibitors

A

Block cyclooxygenase conversion to prostaglandins

72
Q

___ irreversibly inactivates both forms

A

Aspirin

73
Q

Selective inhibitors of ___ are effective treatments for inflammatory conditions (rheumatoid arthritis)

A

COX-2

74
Q

Arachidonic acid is also converted to leukotrienes by ___

A

Lipoxygenases

75
Q

Explain receptor-independent signaling

A

Low molecular weight signaling molecules that cross the plasma membrane and directly modulate the activity of the catalytic domains of transmembrane receptors or cytoplasmic signal transducing enzymes

76
Q

__ __ stimulates guanylate cyclase (generates cGMP (relaxes blood vessels))

A

Nitric oxide

77
Q

Angina symptoms treated with __ __, which is converted to __ __

A

Glyceryl Trinitrate

Nitric Oxide

78
Q

Explain endocytosis

A

Packaging of extracellular materials in vesicles at the cell surface

79
Q

Endocytosis requires __

A

ATP

80
Q

3 types of endocytosis

A
  1. Pinocytosis
  2. Phagocytosis
  3. Receptor-mediated endocytosis
81
Q

Pinocytosis is cell __

A

Drinking

82
Q

Pinocytosis is the:

A

Nonspecific absorption of extracellular fluid

83
Q

Explain how pinocytosis works

A

Membrane caves in, then pinches off into the cytoplasm as pinocytotic vesicle

84
Q

Phagocytosis is cell __

A

Eating

85
Q

Phagocytosis is activated by attachment to:

A

Pathogen-associated molecular patterns (PAMPS)

86
Q

Receptor-mediated endocytosis is __

A

Selective

87
Q

Receptor-mediated endocytosis forms ___ at ___

A

Vesicles (containing receptors)

The surface of the membrane

88
Q

Receptor-mediated endocytosis has ___ coated vesicles (forms polyhedral lattice)

A

Clathrin

89
Q

An example of receptor-mediated endocytosis is

A

Iron transport via transferring receptor

90
Q

Transcytosis is the:

A

Movement of receptors to a different membrane from the one in which it was endycytosed

Biochemistry (6 decks)

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