Chapter 3

Fxn of nucleus

Controls cell activities; stores DNA

Fxn of nucelolus

Makes ribosomes

Fxn of ribosomes

Protein synthesis

Fxn of Smooth ER

Lipid synthesis; detoxification, stores calcium

Fxn of Rough ER

Protein processing/transport

Fxn of golgi apparatus

Modifies and packages proteins

Fxn of lysosomes

Digestion and waste removal

Fxn of mitochondria

ATP/energy production

Fxn of cilia

Move substances across cell surface

Fxn of flagella

Cell movement

Fxn of cytoskeleton

Support shape and movement

Is cytoplasm intra or extracelullar

Extra

Is ICF intra or extracellular

Intra

Other two names for ICF?

Interstitial fluid, cytosol

4 extracellular fluids and where they’re found

1. Interstitial fluid (between cells of a tissue)

2. Synovial fluid (between joints)

3. Plasma (blood)

4. Cerebrospinal fluid (CSF) (Brain and spinal cord)

What organic molecules is the plasma membrane mostly made of

Proteins and lipids

Plasma membrane

Phospholipid bilayer with embedded proteins and cholesterol

What heads face the intra and extracellular fluids? Phillic vs Phobic?

Intra: phillic, extra: phobic

Fxn of plasma membrane

Stabilize membrane

Define glycoprotein and glycolipid

Glycoprotein: Protein with an attached sugar group.

Glycolipid: Lipid with an attached sugar group.

What is the glycocalyx?

Carbohydrate-rich “coating” on the outer surface of the plasma membrane.

3 fxns of the glycocalyx

1. Allows cells to recognize each other

2. Allows communication between cells of the tissue

3. Sticks cells to each other

Which junction forms an impermeable barrier?

Tight

Which junction prevents cells from tearing apart?

Desmosome

Which junction allows cells to communicate with each other?

Gap junction

Name somewhere a tight junction may be found?

Intestine, kidney, bladder

Name somewhere a desmosome may be found?

Cervix of the uterus

Name somewhere that gap junctions would be found?

Embryonic cells, muscle cells, and some nerve cells

What junctions does the heart have?

Gap and desmosome

How do you know contact signaling is taking place?

Direct physical contact

Name one situation where contact signaling is used

Embryonic development

Which is more common, contact signaling or signaling with ligands?

Signaling with ligands

What is a ligand

Chemical msger

3 common ligands

Hormones, paracrine factors, neurotransmitters

Do ligands target one cell or many cells

1

Are ligands extra or intracellular

Extra

Does a paracrine factor act locally or distant?

Locally

Which specific cells release neurotransmitters

Neurons

Which org molecule acts as a receptor in the cell membrane

Proteins

How would you describe the enzyme before the ligand binds to the receptor? Active or inactive?

Inactive

How would you describe the enzyme after the ligand binds to the receptor? Active or inactive?

Active

Besides the ligand binding to the receptor, what else was required to activate the enzyme?

ATP

In what state are ion channels usually?

Closed (inactive)

Which organic molecules in the membrane act as ion channels?

Channel proteins

Which signaling pathway results in the creation of second messengers?

G mediated pathway

Describe the steps in a G-protein signaling pathway.

1. First the ligand binds to the receptor.

2. Ligand binding causes the G protein to break away from the receptor and move across the membrane

3. The G-protein binds and activates the effector protein.

4. The effector protein creates the second messenger.

5. The second messenger changes the function of the cell.

3 common second messengers.

Calcium, cAMP, cGMP

Are second messengers extracellular or intracellular signals?

Intra

3 major components of cell membrane

1. Phospholipid bilayer

2. Cholesterol

3. Proteins

3 outcomes of ligand binding to receptor

1. Activation of enzyme

2. Opening of ion channel

3. Activation of G protein creating second messengers

Neurotransmitters act ..

distant