Unit 1: Cells

Front 1

List types of cells in decreasing order

Back 1

Plant cells, animal cells, prokaryotic cells

Front 2

Explain the fluid part of the fluid mosaic model

Back 2

Things move around, not fixed in place

Front 3

Explain the mosaic part of the fluid mosaic model

Back 3

Built of several components, not arranged in a strict manner

Front 4

Who proposed the fluid mosaic model (and when)

Back 4

Singer and Nicolson in 1972

Front 5

Describe Davidson danielli model

Back 5

Lipid bilayer

Then layer of protein on BOTH sides of the bilayer

Lipids are fixed

Front 6

List evidences leading to falsification of DD model

Back 6

Tech advances

Not all membranes are symmetrical

Different membranes have different functions, compositions

Non aq. Protein layer would not suit aq. Environment

Front 7

What tech advances lead to falsification of dd model

Back 7

Electron microscopy

Cell culture

Front 8

What does EACH phpl molecule have

Back 8

Hydrophilic part

Hydrophobic part

Front 9

Talk about the arrangement of phpl in the membrane

Back 9

A bilayer is formed, phpls are arranged in a shape that requires the least energy to sustain

H-philic portions are pointing out

H-phobic portions are pointing in

Front 10

Why is hydrophilic layer pointing out?

Back 10

The inside of the cell is aq. and we want to make sure that the membrane does not dissolve

Front 11

Glycerol in the phosphate molecule

Back 11

It is a 3 carbon compound

Has 2 fatty acids attached

Highly polar organic alchohol that includes a bond to a phpl group

Front 12

How are hydrophilic heads attached?

Back 12

They are packed together so no large molecules can go through

Front 13

what are integral proteins

Back 13

- They have BOTH hydro philc and phobic areas(amphipathic) to make sure that the protein is not repelled by the membrane

- They have a binding site for cell signalling molecules on the outside of the cell

- have a binding site for peripheral membrane proteins on the inside of the cell

- Transmit messages from outside to inside

Front 14

Describe peripheral membrane proteins

Back 14

- Take messages from integral protein to further into the cell

- can be enzymes

- may be involved in cell adhesion

- located on both sides of the bilayer

Front 15

Describe Glycoproteins and Glycolipids

Back 15

- Used for identification(like a license plate)

- Eg. Blood types

Front 16

Describe cholesterol

Back 16

- Helps to maintain the membrane integrity

- Allows to keep the membrane from freezing or "melting" at extreme temperatures

- Two types:

- HDL(good) - high density lipoprotein

- LDL(bad) - low density lipoprotein

Front 17

Describe Protein channels

Back 17

- Allow certain molecules into the cell or out of the cell

- usually very specific for a certain kind of molecule

- They have specific shape to only allow the "right" molecules through

Front 18

what are the 2 types of transport

Back 18

Active and passive

Front 19

Active vs passive transport

Back 19

Active - requires energy(ATP), movement happens AGAINST the concentration gradient

Passive - happens when there is a difference in concentrations. Movement happens WITH the c. gradient

Front 20

types of passive transport

Back 20

Osmosis and Diffusion

Front 21

Describe diffusion(not f.)

Back 21

Definition: The molecules move RANDOMLY from a region of higher concentration to the region of lower concentration

In living organisms often involves a membrane

Front 22

Facilitated diffusion

Back 22

Definition: type of diffusion involving membrane with specific carrier proteins that are capable of combining with the substance to aid its movement. Ex - Glycose

The carrier proteins DO NOT require energy

It is very specific

Front 23

Describe osmosis

Back 23

Definition: only involves the passive movement of water across a partially permeable membrane.

difference in concentration of solute is what allows the transfer of water

Front 24

what is partially permeable membrane

Back 24

only some particles can move through it

Front 25

hypotonic vs hypertonic vs isotonic

Back 25

HYPO - lower concentration

HYPER - higher concentration

ISO - the concentration is the same

Front 26

what are some factors that affect diffusion

Back 26

Temperature - higher KE (molecules move faster)

Concentration - the molecules have more space to go in the lower concentration area of the cell

Pressure - the force is acting on the molecules

Front 27

How easy is it to move a molecule through the membrane

Back 27

- Larger molecules such as polysaccharides and lipids cannot fit through the membrane(size)

- Polar molecules can have trouble passing through the membrane(polarity)

Front 28

Example of active transport

Back 28

In animal cells, concentration of sodium in the extracellular environment is much higher than on the inside. This is why the cell must use ATP to move sodium.

Front 29

Describe the sodium-potassium pump

Back 29

1. A specific protein binds to the sodium ions.

2. Binding of Na+ causes phosphorylation by ATP. One phosphate from ATP is lost and ADP is formed(only has 2 phosphates)

3. Phosphorylation changes the shape of the protein and Na+ is released on the outer of the cell.

4. extracellular K+ ions bind on the other side and the ph group is released

5.loss of the ph group restores the original shape of the protein and K+ is released

Front 30

what is phosphorylation

Back 30

A biochemical process that involves the addition of phosphate to an organic compound.

Front 31

endocytosis vs exocytosis

Back 31

endo - into the cell

exo - out of the cell

Front 32

Describe the process of endo/exo cytosis

Front 33

Why could endocytosis not occur?

Back 33

If the membrane was not fluid

Front 34

Examples of Endocytosis and describe the process

Back 34

Protein Exocytosis

1. Protein enters the lumen, inner space of ER

2. Protein exits the ER with a vesicle

3. As the protein moves through G. apparatus, it is modified and exits on the TRANS face inside a vesicle

4. Vesicle fuses with the membrane and proteins are proteins are released

Front 35

What are specialized cells

Back 35

They are specialized to perform a specific role/function

Front 36

what is a stem cells

Back 36

it is a cell that has the potential to give rise to specialized cells and has the ability to divide and make copies of itself

Front 37

Explain the term differentiation

Back 37

The process of cell specialization

Front 38

Totipotent stem cells (what they do, ex, and location)

Back 38

Have the ability to give rise to the whole organism

Ex - fertilized egg

location: in the female uterus

Front 39

Pluripotent stem cells (what they do, ex, and location)

Back 39

have the ability to give rise to any type of cell but not an entire organism

Ex - embryonic stem cells

Location: early embryo

Front 40

Multipotent stem cells (what they do, ex, and location)

Back 40

Can become only 1 of a few cell types.

Ex - adult stem cells

Location: virtually any location in the body

Front 41

Adult vs embryonic stem cells

Back 41

A - can differentiate for a prolonged period of time but not indefinitely

E - can differentiate indifinitely

Front 42

Where can adult stem cells be obtained

Back 42

Different tissues in the body but it is difficult

EX. brain stem cells, bone marrow

Front 43

list 3 sources of embryonic cells

Back 43

-Embryos created by IVF for research

- Existing embryonic stem cell lines

-Excess in vitro fertilization(IVF) embryo

Front 44

Problem With stem cells and immune system

Back 44

The markers in the organism can be different from the ones that stem cells have meaning that the organism will think that the organ is harmful and will try to kill it