Endocrine System -- Khan Academy

Describes the steps that occur for a triggered response to occur in a cell with a ligand and integral protein

1. Ligand binds to integral protein 2. Ligand receptor complex created 3. Conformational change to integral protein occurs 4. Intracellular signaling proteins are activated in a cell 5. Intracellular signaling proteins activate a cascade of proteins signals that alter behavior of the cell

What are the 3 types of membrane receptors (this includes the membrane protein)

1. Ligand gated ion channels 2. G-Protein coupled receptor 3. Enzyme linked receptor

What are the 3 major types of hormones

1. Proteins/polypeptides 2. steroids 3. tyrosine derivates

What are 4 common things G proteins help in

1. Regulate immune system 2. Growth, 3. Taste of smell 4. Behavior/mood (serotonin/dopamine)

What is the signaling pathway of a G protein coupled receptor?

1. alpha, beta and gamma subunit bind to each other. 2. Ligand binds to the 7 alpha helices causing a conformational change to G proteins 3. Alpha subunit exchanges GDP for GTP 4. After exchange of GDP to GTP alpha subunit dissociates from beta and gamma subunit 5. Target protein binds to alpha subunit 6. Alpha subunit regulates target proteins and target protein releases signal via 2nd messenger Ex. Target protein = adenylate cyclase with epinephrine being the ligand. This causes ATP and convert to cAMP, with cAMP being the 2nd messenger to relay the target protein signal

What is aldosterone

A steroid that is a major regulation hormone of our body blood volume in our veins, vessels, arteries, etc

What is cortisol steroid?

A steroid that is a stress hormone Increases blood sugar in times of stress for energy and has anti inflammatory functions

What are the hormones released by the posterior pituitary gland

ADH and Oxytocin

What two energy molecules are converted in G protein coupled receptors

ADP and GDP

What is the active for of ADP

ATP (Adenosine triphosphate)

What is ADH

Anti-diuretic hormone, it it the major regulator of fluids in our body

What do the sex hormones assist in, in regards to development

Assist in development of secondary sex characteristics (pubic hair, physical changes)

Why is the word enzyme in the name enzyme linked receptor?

Bc the binding of a ligand to the enzyme linked receptor on the transmembrane protein causes intracellular enzymatic activity

What is the second step of terpene to steroid hormones

Body takes squalene and through a series of cyclization reactions it makes cholesterol

How is hormone concentration collated

By metabolic, excretion and feedback loops (specifically negative feed back loops)

How does the liver regulate hormone concentration

By metabolizing the extra hormone to bile with is ultimately excreted in digestive system (deudenom)

How does the hypothalamus communicate with the posterior pituitary gland

By sending signals to the pituitary gland through stimulation of nerves that run down the pituitary stalk, causing it to release hormones

How are hormones classified

By structure

What occurs if RTK don't work

Can cause trouble in growth and differentiation and lead to cancer.

Does the ligand ion channel have one or multiple binding sites

Can have multiple binding sites

What is the hypophyseal portal system

Capillary system that consist of capillary blood vessels that secretes hormones from hypothalamus to signal the anterior pituaity gland

What is the main lipid steroid hormones derive from

Cholesterol

What are terpenes

Class of lipid molecules that are made of a repeating distinct set of carbon atoms known as isoprene

What is the structure of the G protein coupled receptor?

Contains 7 transmembrane alpha helixes, alpha, beta and gamma subunit.

What is CRH

Corticotrophin releasing hormone, stimulates release of Adrenocorticotrophin by anterior pitiuitary gland to then stimulate adrenal gland so it can release it's hormones

What steroids does the adrenal cortex make

Cortisol, aldosterone, Gonad hormones

What are the two isoprene pyrophosphate that are found in almost all organisms and used in the first step of terpene to steroids

Dimethylallylpyrophosphate and isopentylpyrophosphate

What occurs in step 1 of making steroid hormones our of terpenes

Electrons of 1 pi bond on isoprenepyrophosphate act like a nucleophile and attack a carbon on dimethylallyphosphte to leave, giving us ginylpyrophostphate

What two hormones does estrogen have ovaries make

Estradiol and estrone

What are the sex hormones that the gonads release in females

Estrogen and progesterone

What are the 4 tropic hormones released by the anterior pituitary gland

FLAT = FSH (Follicle stimualing hormone), LH (Lutenizing hormone), ACTH (Adrenocorticotrophin), TSH

How do the kidneys regulate hormone concentration

Filter blood and removes waster of producted of blood through urine

What are the steps to activating a receptor tyrosine kinase.

First binding of signal molecules to RTK causes 2 RTK membranes to associate with each other and create a cross linked dimmer This allows phosphorylation of the tyrosines in RTK that allows intracellular protein to bind and finally signal transduction occurs

What is involved in all of those that have secondary messengers

G - protein channel

What's the largest type/class of membrane receptor

G protein coupled receptors

What is the active form of GDP?

GTP (Guanasine triphosphate)

What are exocrine glands

Glands that secret products into duct

What are endocrine glands

Glands that secrete product into blood stream

What hormone is released when the concentration of glucose is low

Glucagon

Describe the structure of an enzyme linked receptor

Has a pitch fork shape that goes a bit into the intracellular fluid

Describe how secondary messengers allow hormones to react with it's receptors

Hormone binds to a cells receptor that sets off a chain of reactions inside the cell, releasing a secondary messenger inside cell that causes the new desired hormone to release

What is prolactin inhibitory factor

Hormone released by hypothalamus to signal anterior pit gland to release prolactin

What is the growth releasing hormone

Hormone released by hypothalamus to signal anterior pit. Gland to release growth hormone to stimulate growth of long bones and big muscles

What is GnRh

Hormone that is released by hypothalamus and send to anterior pit. Gland through hypophyseal portal system to have pit gland release FSH and LH

Describe how primary messengers allow hormones to react with it's receptor

Hormones crosses cell membrane and binds to receptors inside cytosol or nucleus

What are autocrine hormones

Hormones that function at the cell that makes them

What are direct hormones

Hormones that stimulate body directly

What are tropic hormones

Hormones that stimulate other endocrine glands

What is oxytocin

Hormones that stimulates uterus to contract during pregnancy

What is biosynthesis in regards to steroids and terpenes

How the body uses terpenes as building blocks to create steroids

Where is the control center of the endocrine system, and what does it do

Hypothalamus (specifically the pituitary gland) --> it makes the hormones

Are G protein coupled receptor in euks or proks?

In euks

Where are the protein/polepeptide hormones made

In the rough ER then they are sent to the Golgi apparatus, repacked in vesicles and secreted in designated place

Where is the pancreas located

In the upper part of abdomen

What hormone is released when there is high blood glucose levels

Insulin

What is an example is a protein hormone

Insulin

What is the ligand receptor complex

Integral protein binder to ligand

Are integral proteins specific to ligand or generalized?

Integral protiens are specific to certain ligands

What does the adrenal gland do and where is it located?

Involved in the flight or fight response, by makeing catecholamines, makes steroids , Located on top of the kidneys and has 2 parts 1. Cortex (outside part) 2. Medulla (inside part)

What is the pituitary gland?

Is it a gland controlled by the hypothalamus, it is known as the master gland bc it takes that info (hormone) from the hypothalamus and it directs it to the endocrine gland it has to go to

What is the first step to making steroid hormones our of terpenes

Isoprene is bounded to pyrophosphate

Where does the receptor bind in a ligand ion channel?

It binds anywhere but on the channel opening itself thus it is allosteric

What does the pancreas do

It controls the blood sugar through two hormones, glucagon and insulin

What is the thyroid gland and where is it located

It is located in the neck and wraps around the trachea and it helps regulate metabolism by releasgin T3 and T4

What is an enzyme domain and where is the enzyme domain in an enzyme linked receptor?

It is the tip of the transmembrane protein that in in the intracellular fluid, it is the part that can act as an enzyme

What does an enzyme linked receptor, receptor tyrosine kinases do

It transfers phosphorus from ATP to intracellular proteins and can bind and respons to ligands such as growth factors

What occurs after a ligand binds to the receptor

It triggers the designated response

What binds to a receptor

Ligand (also known as the signal molecule)

What is signal transduction

Ligand binding and sending a signal to tell the cell what to do intracellularly

Do ligand gated ion channels react slowly or quickly to stimulus

Ligand gated ion channels react quickly to stimulus

What do steroid hormones come from

Lipids, with main lipid being cholesterol

Where does step two of terpene to steroid hormones occur

Liver

What organs are involved in regulating hormone concentration

Liver and kidneys

What is aldosterone

Main home network that regulates the body's blood pressure in fluid volume, (steroid hormone)

What is biosynthesis

Multi step enzyme catalyze process where substrate are converted into a more complex products in living organisms

Is the pancreas involved directly with the pituitary gland

No, but it still uses hormones made by it

What is the basal metabolic rate

Number of calories required to keep you body functioning at rest

What are the gonads in females

Ovaries

What is PTH and what does it do and where is it located?

ParaThyroid Hormone --> located behind thyroid 1. Regulates body's blood Ca+ levels

What are the 3 hormones that are direct hormones released by the anterior pituitary gland

Prolactin, endorphins, growth hormones

What type of hormones makes up most of the body's hormones

Protein/polypeptide

What protein regulates the G protein signaling

RGS protein

What enzyme linked receptor plays a big role in growth factors

Receptor tyrosine kinase

What is the most common enzyme linked receptor?

Receptor tyrosine kinase

What are enzyme linked receptors

Receptors that receive signals from environment to instruct cell to do certain things

What do the gonads do

Release sex hormones

How many protiens can be binding in an Receptor tyrosine kinase

Several bc there are at least 4 tyrosines that can be phosphoralated, and a protein can bind to each tyrosine

What are the two important classes of steroid hormones for endocrine glands

Sex hormones and adrenal cortex hormones

What is the molecule that forms the base of all our steroid hormones

Squalene

What is cortisone

Steroid hormone involves in stresss and antiinflmmation effects and increasing carbohydrate metabolism like cortisol

What hormones use primary messengers to react with its specific receptor

Steroids

What are the gonads in males

Testes

What are the sex hormones that the gonads release in males

Testosterone

What two hormones does androgen make

Testosterone and androsterone in testes

What is progesterone

The "pregnancy" hormone , preps the uterus and help have a healthy pregnancy

What part of the pituitary does the hypothalamus intreact with (send it's hormone too)

The anterior part specifically the hypophyseal portal system

What is the endocrine system?

The system that consist of glands that secrete hormones into blood stream so they can circulate from 1 part of the body to a notion part of the body to initiate an effect

Are G protein specific or general

They are very specific

Where do endocrine hormones function

They function at a distance

Where do paracrine hormones function

They function regionally

Do hormones have specific or general receptors

They have very specific receptors, whose location can help us determine the function of the hormone

What are membrane receptors

Thing that are on membrane proteins that help activate the membrane protein and thus allow the outside of the cell communicate with the inside

What are two ways a hormone can react with it's specific receptors

Through primary messengers or secondary messengers

What are tyrosine hormones based off

Tyrosine amino acid

What step happens after we get ginylpyrophostphate from step 1 in terpene to steroid hormones

We repeat this step again with dimethylallylpyrophosphate to get farnesyl pyrophosphate, and continue this till we get squalene

What is a monoterpene

When 2 isoprene come together for.a total of 10 carbons

What is a sequiterpene

When 3 isoprene come together for a total of 15 carbons

What is a divergence

When 4 isoprene come together for a total of 20 carbons

What is a sesterterpene

When 5 isoprenes come together for a total of 25 carbons

What is a tetraterpene

Wwhen 8 isoprenes come together for a total of 40 carbons

What is a triterpene

Wwhwwhen 6 isoprenes come together for a total of 30 carbons

Are the alpha helices and G proteins bounded to each other?

Yes

Can RTK bind to hormones

Yes

Can steroid hormones easily pass through membrane

Yes, bc they are lipid based thus its receptor is inside (uses G coupling)

Can tyrosine derivative hormones also be protein or steroid hormones

Yes, but it has to have tyrosine

Are ligand gated channels transmembrane proteins?

Yes, they go all across the cell membrane