Compartmentalization

Question 1

3 distinct sub cellular regions

Answer 1

Cell membrane (plasma membrane)
Nucleous
Cytoplasm

Question 2

__% of bodily fluid is in the inside of cells

Answer 2

60%

Question 3

Function of the cell membrane

Answer 3

Control what exits the cell and leaves the cell (selectively permeable)

Question 4

What can/can’t move freely through the cell membrane

Answer 4

Can: Small, non-polar, lipid or fat soluble uncharged molecules (move by passive/simple diffusion)
Can’t: Large, uncharged, polar or water soluble and charged molecules need hep (Facilitated by proteins)

Question 5

Hydrophobic

Answer 5

Water hating, non-polar

Question 6

Hydrophilic

Answer 6

Water loving, polar

Question 7

Amphipathic molecule

Answer 7

A molecule with both hydrophobic and hydrophilic portions

Very important in forming the lipid bilayer

Question 8

How does cholesterol affect the plasma membrane

Answer 8

Cholesterol decreases fluidity/increases rigidity. This decreases permeability since the bilayer is rigid.

Less cholesterol will increase fluidity and permeability.

Question 9

Integral proteins (intrinsic)

Answer 9

Have at least 1 hydrophobic region that anchors them to the hydrophobic core of the lipid bilayer. The hydrophilic portion associates with aqueous fluid either outside or inside the cell.
Some stick only partway into the membrane and others span the entire width (transmembrane protein)

Question 10

Transmembrane protein

Answer 10

Protein that spans the entire width of the membrane

Question 11

Peripheral proteins (extrinsic)

Answer 11

Surface protein (can be on either side of the membrane) that is temporary. Attached to integral proteins or the hydrophilic heads of phospholipids. They do not associate with the hydrophobic core

Question 12

Difference between integral (intrinsic) proteins and peripheral (extrinsic) proteins

Answer 12

Integral proteins anchor themselves to the hydrophilic core, either only on one side, or spanning the entire membrane.

Peripheral proteins attach to the integral proteins on either side of the membrane and do not associate with the hydrophilic core. They are temporary.

Question 13

Function of carbohydrates on the cell surface

Answer 13

They are usually attached to proteins (glycoproteins) or lipids (glycolipids) and provide cushioning/protection, involved in cell recognition and connect/join two cells together.

Question 14

2 examples of extracellular fluids

Answer 14

Intercellular/interstitial or intravascular

Question 15

Fluid within the cell

Answer 15

Intravascular

Question 16

Nuclear envelope consists of

Answer 16

2 lipid bilayer membranes
Top layer- Outer lipid bilayer that is continuous with the rough endoplasmic reticulum.
Inner layer- Inner lipid bilayer that is lined by the nuclear lamina, which is protein that organizes DNA

Question 17

Job of nuclear lamina

Answer 17

Protein that organizes DNA found in the inner layer of the lipid bilayer within the nuclear envelope.

Question 18

Semifluid matrix found inside the nucleus

Answer 18

Nuceloplasm

Question 19

Chromatin

Answer 19

DNA + protein within the nucleoplasm

Question 20

Nucleolous

Answer 20

Within the nucleoplasm, site of rRNA and ribosome synthesis

Question 21

Fibrous proteins found in the cytoskeleton

Answer 21

Microtubules
Actin filaments
Intermediate filaments

Question 22

Role of the cytoskeleton

Answer 22

Provides structure and support inside the cell. Helps materials inside the cell move by kinesin and or dyneine

Question 23

Ribosome subunits

Answer 23

large subunit (60s) and small subunit (40s)

Only composed of rRNA and proteins. Does not have a surrounding membrane (not membrane bound)

Question 24

Cisternae

Answer 24

a series of tubules and flattened sacs. Found in the endoplasmic reticulum and golgi apparatus

Question 25

Role of the smooth ER

Answer 25

• lacks ribosomes
• Lipid processing center. Turns toxic lipid/fats into water soluble substances
• High presence in liver (detoxifies drugs/alc)
• Uses Ca2+ from the cytosol

Question 26

What is the golgi apparatus made of

Answer 26

Cisternae (tubules and flattened sacs) and the membrane is a lipid bilayer.

Question 27

Role of the golgi apparatus

Answer 27

Modiefies proteins received from the ER. Glycosylation.

Question 28

Cis and trans sides of the golgi

Answer 28

Cis- receiving side (longer) and trans- shipping side (smaller)

Question 29

What is the mitochondria composed of

Answer 29

Double membrane, mitochondrial matrix and circular DNA from mom. (can synthesize rRNA, tRNA, and mRNA)

Inner membrane forms many deep folds (Cristae) with fluid inside and the outer is the surface.

Question 30

Which organelle plays a role in apoptosis

Answer 30

mitochondria

Question 31

pH of lysosome

Answer 31

Acidic ~5.

Contains enzymes that break down old cellular components or foreign particles.

Question 32

Lysosome role

Answer 32

Recycle/trash.
Surrounded by a membrane
Contains enzymes to break down particles
pH ~5

Question 33

Peroxisomes

Answer 33

• Surrounded by lipid bilayer (good bc selective permeability)
• Involved in a variety of reactions such as fatty acid oxidation, neutralizing free radicals, myelin synthesis, and cholesterol synthesis.