Brainscape's Knowledge GenomeTM

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


See full index

BIOL 103 > Cellular Communication > Flashcards

Cellular Communication Flashcards

1
Q

What do signalling pathways allow animals to do?

A

Sense and respond to the environment

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

What is cell signalling essential for?

A

homeostasis

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

What is a defining factor in determining a cell signalling factor and how it works?

A

Solubility

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

What is hydrophillic?

A

Able to dissolve in aqueous solutions.

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

What is hydrophobic?

A

Can’t dissolve in aqueous solutions, known as “fat loving” (lipidphillic)

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

Can hydrophobic factors be contained within cells? Detail why yes or no.

A

They CAN’T be contained within cells, due to the lipid cellular membrane (since it would escape). They escape as soon as they would be synthesized (created), so they can not be stored pre-made. Therefore any signal to release the factor is slow as it requires the cell to produce the factor only when needed.

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

Can hydrophillic factors be contained within cells? Detail why yes or no.

A

Yes they can be stored, as it can be contained by the lipid cell membrane. Therefore, they can be made independent of need. So once a signal is received for it, it can be released immediately.

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

Which is it easier for to travel to the target tissue, hydrophobic or hydrophilic factors? Detail why.

A

Hydrophilic: It is able to dissolve in the extracellular fluid and easily travel to the target tissue

Hydrophobic: “Harder” since it is unable to dissolve in the extracellular fluid, and needs to bind to a carrier protein to travel to the target tissue

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

What happens when they hydrophobic/hydrophilic factors reach the desired cell? Which is easier to get in and what effects does it trigger when entering the cell?

A

Water soluble (hydrophilic) are unable to get into the cell due to the lipid membrane so they must initiate a response by binding to a receptor on the cell membrane. This triggers a signalling cascade that uses second messengers once inside the cell.

Fat soluble factors (hydrophobic) are able to freely diffuse across the cell membrane, so they receptors are put inside the cell. Fat soluble factors also tend to bind to receptors that trigger change in gene expression directly.

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

Water soluble factors are…?

A

proteins

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

Fat soluble factors are…?

A

steroids

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

Are proteins the same in all animals?

A

No they are not. They can have the same proteins but proteins can be different in specific structures but have a similar evolutionary lineage and therefore play different roles in different animals.

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

Are all factors hormones?

A

No they are not since a hormone is a factor that works through (travels) through the blood. Factors may include hormones, but not all factors are hormones. This is also because factors can work locally, and not have to travel large distances through the blood stream.

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

Does Acetylcholine act locally or far distances?

A

Acetylcholine is released by neurons but only acts locally.

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

Describe the elements of the endocrine signalling pathways.

A
  1. Synthesis: a hormone (a ligand) is synthesized in an endocrine gland (it is produced)
  2. Secretion: once it is produced, it has to be secreted. It somehow escapes from the tissue.
  3. Transport: it travels to the target tissue.

*after these (previous) steps is when it becomes a ligand

  1. Reception: binds a receptor at the target tissue (once a ligand binds to a receptor it initiates a response)
  2. Transduction: connects receptor to effector. The change in shape of the receptor causes some sort of downstream effect.
  3. Response: ultimate consequence of the signalling cascade. This could include the activation of enzymes, phosphorylation of receptors, etc.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Define a ligand.

A

A general term for a chemical that binds to some sort of receptor.

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

What does control of synthesis of a hormone depend on?

A

On the chemistry of the hormone.

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

Where does the synthesis of a hormone occur?

A

an endocrine gland.

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

What are proteins/polypeptides encoded by?

A

genes. the synthesis depends if their genes are turned on or off.

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

What do ells that secrete hydrophilic hormones have to do?

A

They have to be able to get them outside of the cell, this involves vesicles secreted by exocytosis.

Once inside the cell, you have to make the vesicles which occurs via the Golgi pathway and intercellular sorting routes.

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

What happens when a cell receives a signal to release hormones?

A

Responds to the bag of hormones that have come to the cell by moving vesicles to the surface, and causing it to diffuse through the cell membrane.

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

What is exocytosis?

A

process by which cells move materials from within the cell into the extracellular fluids. occurs when a vesicle fuses with the plasma membrane, allowing its contents to be released outside the cell.

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

Are all chemicals that are synthesized by enzymes be stored?

A

They may or may not be stored, depending on their lipid solubility.

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

What is the most common protein in the blood?

A

Albumin.

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

What is globulin?

A

it is a specialized carrier protein, that carriers a hormone from place to place.

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

When can a hormone interact with a receptor?

A

when it hits the target tissue.

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

How can a tissue control its response to a hormone?

A

by deciding wether or not to make a receptor for that hormone.

28
Q

What happens once a hormone (or ligand) bind to a receptor?

A

it experiences a conformational change (change in shape). This change in shape can make the receptor a better or worse protein at binding to the promoter of a target gene.

29
Q

What does a membrane receptor do?

A

It binds to the hormone on the outside, and causes changes in the receptor on the inside. This new shape could also make it a better or worse enzyme, or allow it to make a new docking site for a protein.

30
Q

What are receptors specialized to do?

A

To bind to things that resemble the natural ligand.

31
Q

What do interactions between receptors and ligands depend on?

A

Depends on their being a suitable receptor and that the hormone is at a high enough concentration to bind to the receptor.

32
Q

How can cells alter their sensitivity to hormones?

A

they are able to alter their sensitivity to hormones by making more or different receptors (by changing their affinity to how effectively the receptor binds to the hormone).

33
Q

How can hormone receptors be affected by other processes?

A

Environmental chemicals that also bind (these ligands aren’t hormones but have enough structural similarity that it can bind with its receptor). This can include agonists and antagonists.

34
Q

What are agonists?

A

Environmental chemicals may act as an agonist by binding to the receptor but still trigger the same response of the hormone, so nothing really changes.

35
Q

What are antagonists?

A

Environmental chemicals mat act as an agonist by binding to the receptor, but prevents the natural hormone from binding making it ineffective.

36
Q

What are phytoestrogens?

A

steroids found in plants that resemble the natural estrogen found in animals and influence normal estrogen signalling pathways. They can act antagonists or agonists.

37
Q

Explain the minnow fish example and how this is an example of phytoestrogens.

A

Some genetically male minnows may receive enough estrogen to make it develop as if it were a female. Making it intersex. Environmental estrogen was exposed at an early developmental stage that “mucked up” the signalling pathways that determined the development of “maleness” and “femaleness”. Therefore in their testes you would find eggs. This can manifest as a problem of feminization of the population which impairs the longterm health and breeding effectively.

38
Q

What does estrogen affect?

A

only vertebrates. and it has a greater effect on males more than females.

39
Q

Do plants possess estrogen like compounds?

A

Yes, which can impact many vertebrates in their environment.

40
Q

What is anthropogenic?

A

environmental changes caused by humans, directly or indirectly.

41
Q

What is receptor?

A

a general term for something that binds a ligand. hormone receptors bind hormones,

42
Q

What are all hormone receptors?

A

Proteins and each have genes that encode them .

43
Q

What does a change in shape usually cause for hormone-receptor binding?

A

It is usually linked to another function.

44
Q

What happens to the receptor acytecolene when it binds to its ligand?

A

It triggers a change in shape that permits it to become an open ion channel for sodium.

45
Q

Describe various situations of receptors and what their possible functions might be depending on the receptor type.

A

Some can work as a docking sites for other proteins, and binding can make it a better docking site.

Receptors can be enzymes so that the binding of ligands changes the catalytic activity of the receptor.

Many of the factors we talk about work by binding receptors that interact with a trimeric protein complex called the G-protein.

46
Q

What happens when receptors possibly bind to transcription factors?

A

When they bind to their ligand, this might trigger movement from the cytoplasm to the nucleus. Or it may cause a change in affinity of the transcription factor for the promoter.

47
Q

Describe what happens when a receptor that is an enzyme binds to its ligand.

A

The binding of the ligand causes the receptor to phosphorylate the relay molecule (another protein). The relay protein goes onto activate a protein kinase which uses ATP to phosphorylate a target protein. The protein kinase goes onto activate many proteins of its own, and this signalling pathway is amplified at each step.

48
Q

Describe what happens when the receptor binds to a G-protein.

A

This goes on to cause the G-protein (the interaction) to activate it and then activate another protein. This other protein that is activated could be kinase, and then this would result in an amplified signalling cascade.

49
Q

What are antagonistic controls?

A

the action of any organism that suppresses or interferes with the normal growth and activity of a plant pathogen, such as the main parts of bacteria or fungi.

50
Q

Describe how glucose is controlled by antagonistic controls, and which each of those controls are.

A

Blood levels are mainly controlled by the two following hormones: insulin and glucagon.

Insulin: reduces blood glucose levels when they’re high
Glucagon: increases blood glucose when low

Both of these hormones are synthesized by different cell types in the pancreas, and they are both peptides so there are genes that code for both. But both of these bind to different receptors and their receptors are found in different tissues. Muscles are an important target for insulin as the receptor triggers the recruitment of glucose transporters to the cell membrane which causes the muscle to increase glucose uptake (absorption).

Level of glucose in the blood reflects the balance of activities of these hormones and the effects on receptors at the target tissues.

51
Q

What are tropic hormones?

A

They are hormones where the main job is regulating the levels of other hormones. An example is FSH, which is a hormone that effects the synthesis of sex steroids.

52
Q

What are endocrine glands?

A

tissues that secrete hormones into the circulating fluids, blood, or extracellular fluids. Animals differ in terms of where the hormones are produced and what various hormones are secreted.

53
Q

Describe the variation of uses or Prolactin in animals?

A

It is for milk production in animals, iron and water balance in fish, etc.

54
Q

Describe the hypothalamus.

A

It is a region of the brain that sits below the thalamus and is a collection of neurons, cell bodies or neurons that are separated into clusters called nuclei. Cell bodies have dendrites that run in one direction to receive information and have axons that run to other regions to send information. In some cases axons can go to other regions of the brain. Axons can also be sent to other tissues, such as. the liver, via spinal nerves, and some could also be sent down to the pituitary gland.

55
Q

How do some hypothalamic neurons release their factors?

A

They release them into the capitally bed to be sent to distant tissues. Factors are considered hormones in this case, due to the distance involved.

Can also be referred to as neuroendocrine factors.

56
Q

Describe the pituitary gland (generally).

A

it is really a combo of 2 glands by what they secrete and how they communicate with the hypothalamus. The two parts are the posterior and anterior pituitary.

57
Q

Describe the posterior pituitary and its connection with the hypothalamus.

A

It is a collection of termini of axons coming from the hypothalamus. Hypothalamic neurons make their secretion in hypothalamus, then use their axons to send their secretions to the capillaries that run through the posterior pituitary gland. From this capillary bed, they make their way to the rest of the body.

58
Q

Describe the anterior pituitary gland and its connection with the hypothalamus.

A

The communication this gland has with the hypothalamus is via a portal vessel. Hormones are released to the capillary in the hypothalamus and travel through the portal vessels into the capillaries of the anterior pituitary when they trigger the release of pituitary hormones into the circulation. these hypothalamic factors are tropic hormones since they triggers the release of other hormones.

59
Q

What is a portal vessel?

A

blood vessels that begin and end in a capillary do not fit the definition of an artery or vein, so they are called portal vessels.

60
Q

What is the combo of the hypothalamus and pituitary gland called?

A

HP Axis and it controls many homeostatic functions.

61
Q

What is one of the most important targets of the HP axis?

A

The adrenal gland

62
Q

What is the adrenal gland?

A

it is a gland that sits on top of the kidney, and good for regulation. It is produced by most vertebrates. The cells producing these hormones are varied in vertebrates, and some are scattered within kidney region. Our adrenal gland is known to produced the epinephrine, which is our flight or fight response.

63
Q

What is responsible for secreting steroids?

A

Our cortex, each region of the cortex has a different combo of enzyme in order to make different steroids.

64
Q

What is the HP axis and adrenal gland signalling called?

A

the HPA axis and this is an example of how tissues communicating with each other is able to cause an appropriate response in the right time frame and magnitude.

65
Q

Describe the similarities and differences for the sex hormones in females and males.

A

Both males and females have similar hypothalamus, and use the same response signals to the same hormones. Both the ovary and testes have the same receptors for receiving LH and FSH.

Differences: both of their receptors are wired differently. females are activated to make the steroid on its own and testes make different steroids since they have diff enzymes.

BIOL 103 (12 decks)

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