Brainscape's Knowledge GenomeTM

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


See full index

My Packs: Science (Biology Olympiad) > (Cell) Cell Communication > Flashcards

(Cell) Cell Communication Flashcards

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

The series of steps by which a signal on a cell’s surface is converted to a specific cellular response is called:

A

Signal Transduction Pathway

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

What are the two forms of communication by direct contact between cells?

A

Cell junctions

Cell-cell recognition

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

Describe cell junctions

A

Both animals and plants have cell junctions that allow molecules to pass readily between adjacent cells without crossing plasma membranes

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

Describe cell-cell recognition

A

Two cell sin an animal may communicate by interaction between molecules protruding from their surfaces

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

What cells can communicate via cell-cell recognition?

A

Animal cells

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

What cells can communicate via cell junctions?

A

Animal and plant cells

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

What are two types local signalling?

A

Paracrine signalling

Synaptic signalling

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

Describe paracrine signalling

A

A secreting cell acts on nearby target cells by discharging molecules of a local regulator (a growth factor, for example) into the extracellular fluid

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

Describe synaptic signalling

A

A nerve cell releases neurotransmitter molecules into a synapse, stimulating the target cell

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

What is the main form of long-distance signalling?

A

Hormonal signalling

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

Describe hormonal signalling

A

Specialized endocrine cells secrete hormones into body fluids, often the blood. Hormones may reach virtually all body cells

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

What are the three stages of cell signaling?

A

1 Reception
2 Transduction
3 Response

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

Describe reception (step 1 of cell signalling)

A

The target cell’s detection of a signalling molecule coming from outside the cell

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

What does it mean for the chemical signal to be “detected”?

A

When the signalling molecule binds to a receptor protein located at the cell’s surface or inside the cell

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

Describe transduction (step 2 of cell signalling)

A

The binding of the signalling molecule changes the receptor protein in some way, initiating the process of transduction

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

Describe response (step 3 of cell signalling)

A

The transduced signal finally triggers a specific cellular response

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

What does the signalling molecules behave like?

A

Ligands

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

What are ligands?

A

The term for a molecule that specifically binds to another molecule, often a larger one

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

What are three major types of membrane receptors?

A

G protein-coupled receptors
Receptor tyrosine kinases
Ion channel receptors

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

Where are intracellular receptor proteins found?

A

Found in either the cytoplasm or nucleus of target cells

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

What do G protein-coupled receptor proteins look like?

A

Each have 7 alpha-helices spanning the membrane

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

What diseases are caused by the interference with G-protein function? (3)

A

Cholera
Pertussis (whooping cough)
Botulism

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

What side of the membrane is the G-protein attached to?

A

The cytoplasmic side of the membrane

24
Q

What two guanine nucleotides serve as the on-off switch for the G-protein?

A

GDP and GTP

25
Q

What does GTP stand for?

A

Guanosine triphosphate

26
Q

What guanine nucleotide is bounded to the G-protein when it is inactive?

A

GDP

27
Q

What are the three main components of the G protein-coupled receptors?

A

G protein-coupled receptor
G protein
Enzyme

28
Q

What happens when the appropriate signalling molecule attaches to the G protein-coupled receptor?

A

Binds the inactive G protein, replacing GDP with GTP, activating the G protein

29
Q

What happens when the G protein is activated? (2)

A

Diffuses along membrane, and binds to an enzyme, altering the enzymes shape and activity
When enzyme is activated, it can trigger the next step in a pathway leading to a cellular response

30
Q

After activating the enzyme, what happens to the G protein?

A

Serves as an enzyme (GTPase), hydrolyses the GTP and GDP, and becomes inactive again

31
Q

Receptor tyrosine kinases belong to a major class of plasma membrane receptors characterized by what?

A

Having enzymatic activity

32
Q

What is a kinase?

A

An enzyme that catalyses the transfer of phosphate groups

33
Q

What part of the receptor protein extending into the cytoplasm functions as what in receptor tyrosine kinases?

A

Tyrosine kinase

34
Q

What does tyrosine kinase do?

A

Catalyses the transfer of a phosphate group from ATP to the amino acid tyrosine on a substrate protein

35
Q

Identify the extracellular, membrane spanning and intracellular components of receptor tyrosine kinase proteins

A

Extracellular: Ligand-binding site
Membrane spanning: Alpha-helix
Intracellular: Tail, composed of multiple tyrosine

36
Q

Before signalling molecule binds, the receptors exist as __________ ____________

A

Individual polypeptides

37
Q

When a signalling molecule attaches, what happens to the receptor polypeptides?

A

Causes two receptor polypeptides to associate closely with each other, forming a dimer (dimerization)

38
Q

What does the dimerization of receptor tyrosine kinase proteins do?

A

Activates the tyrosine kinase region of each polypeptide; Each tyrosine kinase adds a phosphate from an ATP molecule to a tyrosine on the tail of the other polypeptide

39
Q

Where do the activated tyrosine kinases give their phosphate to?

A

Given to relay proteins, activating them and triggering a transduction pathway, leading to a cellular response

40
Q

What is a ligand-gated ion channel?

A

A type of membrane receptor containing a region that can act as a “gate” when the receptor changes shape

41
Q

Some ligand-gated ion channels are controlled by electrical signals instead of ligands, what are these called?

A

Voltage-gated ion channels

42
Q

What are ligand-gated ion channels and voltage-gated ion channels crucial in?

A

The nervous system

43
Q

What special proteins control which genes are turned on?

A

Transcription factors

44
Q

How can intracellular receptors get through the phospholipid bilayer?

A

Hydrophobic enough

Small enough to cross

45
Q

What are two examples of hydrophobic chemical messengers?

A

Steroid hormones

Thyroid hormones

46
Q

What is an example of a signalling molecule small enough to pass through the phospholipid layer?

A

Nitric oxide (NO)

47
Q

How does testosterone turn on genes? (5)

A

The steroid hormone testosterone passes through the plasma membrane
Testosterone binds to a receptor protein in the cytoplasm, activating it
The hormone-receptor complex enters the nucleus and binds to specific genes
The bound protein acts as a transcription factor, stimulating the transcription of the gene into mRNA
The mRNA is translated into a specific protein

48
Q

What is the general name for an enzyme that transfers phosphate groups from ATP to a protein?

A

Protein kinase

49
Q

What are enzymes that can rapidly remove phosphate groups from proteins called?

A

Protein phosphatases

50
Q

What is the process of removing phosphate groups called?

A

Dephosphorylation

51
Q

What are the 5 steps of the phosphorylation cascade?

A

A relay molecule activates protein kinase 1
Active protein kinase 1 transfers a phosphate from ATP to an inactive molecule of protein kinase 2, thus activating this second kinase
Active protein kinase 2 then catalyses the phosphorylation (and activation) of protein kinase 3
Finally, active protein kinase 3 phosphorylates a protein that brings about the cell’s response to the signal
* Enzymes called protein phosphatases (PP) catalyse the removal of the phosphate groups from the proteins, making them inactive and available for reuse

52
Q

Many signalling pathways also involve small, nonprotein, water-soluble molecules or ions called ______ __________

A

Second messengers

53
Q

What are the two most widely used second messengers?

A

Cyclic AMP (cAMP) and Calcium ions (Ca2+)

54
Q

What is cAMP converted from? By what?

A

cAMP is converted from ATP

Converted by the enzyme adenylyl cyclase

55
Q

What enzyme inactivates cAMP to AMP?

A

Phosphodiesterase

56
Q

What is the immediate effect of cAMP?

A

Usually the activation of serine/threonine kinase called protein kinase A

My Packs: Science (Biology Olympiad) (14 decks)

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