1020 MODULE 3 THE CELL

Question 1

Golgi apparatus

Answer 1

responsible for packaging proteins from rough ER to membrane-bound vesicles
- contains two vesicles produced by Golgi bodies
1. Secretory vesicles: transports proteins into the cell membrane
2. Storage vesicles: contains contents of lysosomes

Question 2

Ribosomes

Answer 2

responsible for manufacturing proteins from amino acids under the control of the cell’s DNA
- fixed ribosomes fixed to er and makes proteins
free ribosomes- float in cytoplasm

Question 3

lysosome

Answer 3

• are a type of storage vesicle produced by Golgi bodies
• have enzymes used to destroy the damaged organelles

Question 4

Mitocondria

Answer 4

• produces ATP
  -powerhouse of the cell

Question 5

Endoplasmic Reticulum

Answer 5

• site for the synthesis, packaging and transporting of proteins and lipids
  rough er- site for protein synthesis
  smooth er- site for lipid synthesis because it lacks ribosomes and ribosomes are responsible for manufacturing proteins from amino acids under control of DNA

Question 6

Cell membrane

Answer 6

• is selectively permeable
  -regulates the transport of substances in and out of the cell

Question 7

Centriole

Answer 7

• directing the movement of DNA strands during the process of cell division

Question 8

Nucleolus

Answer 8

contains DNA for producing RNA found in ribosomes

Question 9

What can penetrate the cell membrane

Answer 9

molecules and ions

Question 10

What cannot penetrate the cell membrane

Answer 10

proteins, nucleotides, and other large macromolecules

Question 11

Phospholipid

Answer 11

• the phospholipid molecule is made up of a hydrophobic lipid and fatty acid tail and a hydrophilic phosphate head.
• when thrown in the water, the tail goes in and aligns itself since it is hydrophobic and the heads are towards the outside.
• then this creates a lipid bilayer
  -this is why some water and water-soluble particles cannot get in like ions or glucose but fat-soluble substances like o2 and co2 can get in.

Question 12

Membrane proteins

Answer 12

1. receptors- attachment of chemical hormones and neurotransmitters
2. Enzymes- chemical reactions help with the breakdown of molecules
3. Ion channels- help water-soluble substances to go in
4. membrane transport- transport of molecules across cells
5. Cell identify markers- antigens like foreign particles that stimulate immune system

Question 13

Most important function of proteins

Answer 13

helps transport substances across the membrane

Question 14

Different ways to cross membranes

Answer 14

• facilitated diffusion
• active transport
• diffusion through protein channels
  -diffusion through lipid bilayer
  -endo and exocytosis

Question 15

Facilitated diffusion

Answer 15

• the movement of specific molecules across the membrane through protein channels
  does not require ATP because it is moving down the concentration gradient

Question 16

Facilitated diffusion continued.

Answer 16

• water- soluble large substances cannot pass through or diffuse through the lipid bilayer.
  -they are also too large to pass through the protein channel.
• this specific molecule attaches itself onto the protein channel and forces it to change the shape which initiates the opening of the channel

Question 17

How does facilitated diffusion differ from simple diffusion

Answer 17

• it differs because unlike simple diffusion, the rate of transport is limited due to the number of protein channels

Question 18

Active transport

Answer 18

• the movement of specific molecules across the cell membrane through protein channels.
• this requires ATP because the molecules are moving against the concentration gradient so low to high.
  ex sodium-potassium pumps

Question 19

Diffusion of a water-soluble substance through membrane requires what?

Answer 19

pore, channel, concentration gradient

Question 20

Rate of movement of molecules through protein channels are limited by what factors

Answer 20

• the size of the protein channel
• greater the electrochemical gradient
• number of cell membrane
• the charge on the molecule

Question 21

recallll process of facilitated diffusion

Answer 21

• protein binds with a molecule
• the shape of protein channel changes
• molecule moves across the membrane

Question 22

Osmosis

Answer 22

• the movement of water from high to low concentration so down the concentration gradient

Question 23

What factors affect osmosis across the cell membrane

Answer 23

• pressure gradient
• the concentration gradient of solute in intercellular and interstitial
• the permeability of the membrane to solute in intercellular and interstitial

Question 24

what particle causes osmosis

Answer 24

osmotically active particle

Question 25

Tonicity

Answer 25

the ability of the solution to cause cells to lose or gain water SO CAUSE OSMOSIS

Question 26

Isotonic

Answer 26

concentration in and out the cell is the same

Question 27

Hypotonic

Answer 27

• low concentration than cellular fluids
• will cause osmosis in the cell and swell

Question 28

Hypertonic

Answer 28

• high concentration than cellular fluids
• causes osmosis to exit and shrink

Question 29

types of membrane potentials

Answer 29

• equilibrium potential
• action potential
  -resting membrane potential

Question 30

what is membrane potential

Answer 30

the ionic charge difference in and out the cell

Question 31

equilibrium

Answer 31

2 factors
concentration gradient and electrical concentration gradient
- when the forces are equal in magnitude and opposite in direction, then there is no net movement

Question 32

resting membrane potential

Answer 32

cells potential at rest

Question 33

action potential

Answer 33

cells potential in action

Question 34

different resting - equilibrium potentials

Answer 34

• Na+ +60 mV
• K+ -90mV
• Cl -70mV
• resting membrane potential = -70 mV

Question 35

Functions of the Sodium- Potassium Pump

Answer 35

• to balance equilibrium and 3 Na will try to get out and 2 K will get in