Hormones/Signal Transduction Flashcards Preview

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Flashcards in Hormones/Signal Transduction Deck (64)
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1

What two hormones does the pancreas produce?

Insulin and Glucagon

2

What is the role of insulin and glucagon

Control glucose in the blood

3

What does insulin control

Insulin is produced when blood glucose levels needs decreasing

4

What does glucagon control

Glucagon acts if there is too little glucose in the body

5

Where is insulin produced??

Beta cells of the pancreas

6

Where is glucagon produced??

Alpha cells of the pancreas

7

Explain negative feedback if there is an increase in blood glucose

Stimulus- Increase in blood glucose
Receptor-Chemorecptor
Control Centre-Pancreas
Effector- Pacreatic beta cells will release insulin
Response-Liver and muscle cells uptake glucose and store as glycogen
Feedback- Blood sugar levels decrease

8

Explain negative feedback in regards to, too little glucose in the blood

Stimulus- decrease in blood glucose
Receptor-Chemorecptor
Control Centre-Pancreas
Effector- Pacreatic alpha cells will release glucagon
Response-Liver and muscle cells will break down glycogen and release as glucose
Feedback- Blood sugar levels increase

9

Explain how insulin promotes the uptake of glucose

Changes the permeablity of the cell membrane to glucose

10

Why do cells need to communicate

Control and regulation of systems

11

What are signalling molecules also known as??

Ligands

12

What are receptors and hormones

Specific

13

What are the three types of signals??

Autocrine signals
Paracrine Signals
Endocrine Signals

14

Define Autocrine Signals

A cell secretes a hormone into extracellular fluid and binds to its own receptors

15

Define Paracrine Signals

Signals being released by cells into extracellualr medium acts on nearby target cells, so this type of signal is a local signal.

16

Define Endocrine Signals

Signals that are produced in the endocrine gland are secreted in the blood stream, therefore distributed throughout the whole body, but only stimulate those with specific receptors

17

Defintion for Hormone

An organic molecule produced in a cell, either acting within the cell or diffusing or being transported to other cell. Hormones travel via extracellular fluid and act on specific target cells.

18

Where do hormones usually travel

In the blood stream of tissue fluid

19

What are the three different classification of hormones?

-Steroid
-Protein/peptide
-Amino acid derivative

20

Explain steroid hormones

-Tend to have a long life span
-Created on demand from precursors in the cell
-Made from chloesterol therefore lipophilic and hydrophobic
-Steroids pass through the cell membrane via simple diffusion
-Need a carrier protein when travelling through blood

21

Example of a steroid hormone

testoesterone

22

Explain Protein/Peptide Hormones

-Made in advance and stored in cells secretory vesciles
-Cannot pass through the membrane so they leave via exocytosis
-Short life span
- They are hydrophilic and can easily travel through the blood stream but need assistance when passing through the membrane

23

example of protein/peptide hormones

Adrenaline

24

Explain Amino Acid Dervative Hormones

-Small molcules that have the same structure as an amino acid
- Made in advance and stored in the secretory vescilces, leave via exocytosis.
-Short Life span
-Water soluble so they can travel through the blood stream easily but need assitance when passing through the cell membrane

25

Are hormones slow or fast

Slow

26

Do they work for a long period or time or short?

Generally long

27

Where are steriod receptors in regards to the cell?

Lipid based hormones are able to pass through the membrane easily and therefore their receptor is located on the inside of the cell in the cytosol.

28

Where are the peptide and amino hormones located?

-Situated on the outside of the cell.
-This is due to not being able to pass through the membrane
-The receptors then activate a protein on the inside of the membrane

29

Define Signal Transdution

Refers to the cascade of events originating outside the cell in leading to a specific cellular response. This is the process in which a cell converts one kind of kind into another by a series of relay molecules.

30

Explain the steps in signal transduction

-Signal is recieved
-Signal is amplified
-Transduction
-Response
-Feedback (possible)