Module 3- Human cell

Question 1

what is the purpose of the golgi apparatus?

Answer 1

-to package proteins from the RER to VESICLES

Question 2

what are the 2 kinds of vesicles produced by golgi?

Answer 2

1) secretory vesicles –> transport proteins to cell membrane to be transported outside of cell
2) storage vesicles –> stores contents inside cell
ex. Lysosomes–> contain enzymes inside cell to digest and destroy bad things that enter

Question 3

what are the 2 kinds of ribosomes?

Answer 3

1) fixed ribosomes–> attached to ER (endoplasmic reticulum)
2) free ribosomes–> float in the cytoplasm of cell

Question 4

what is the purpose of ribosomes?

Answer 4

• little bumps of rNA + protein

- make protein from aa’s, controlled by DNA

Question 5

what is the purpose of the endoplasmic reticulum (smooth and rough?)

Answer 5

1) rough ER–> covered by ribosomes
- makes proteins and packaged to send to golgi
2) smooth er–> no ribosomes
- makes lipids and fatty acids

Question 6

purpose of the mitochondria

Answer 6

• makes most of ATP in body

- makes ENERGY YEA

Question 7

what is the nucleolus

Answer 7

a dense body inside the nucleus that specifically makes rNA for ribosomes

Question 8

what does cell membrane being ‘selectively permiable’ mean?

Answer 8

• only molecules and ions can pass thru, not large proteins

- prtoeins can make channels/pores for other things to get in

Question 9

what is the phospholipid bilayer

Answer 9

hydroPHILIC head
hydroPHOBIC tail
head on outside, tails on inside

Question 10

what kind of molecule can easily bipass the cell membrane? which kind need a protein channel to enter?

Answer 10

lipid soluable substances (ex. oxygen, co2, steroids, hormones) can diffuse stragiht thru
water soluable things like glucose, ions, etc need channels to enter

Question 11

what are the methods things can cross membrane?

Answer 11

1) ENDOcytosis (enter cell) or EXOcytosis (exit cell)
2) diffusion thru lipid bilayer (fat sol only)
3) diffusion thru protein channels (water sol only)
4) facilitated diffusion –> water sols that are too big for protein channels (protein carriers change shape to let in, no energy needed but can get clogged up)
5) active transport–> needs ATP to move things UP the mgrad, against the diffusion flow ex. na/k pump

Question 12

what is osmosis

Answer 12

water moving down its mgrad

water will move to an area of LOW solute mgrad to HIGH solute mgrad

Question 13

what is a solute

Answer 13

the substance being DISSOLVED in liquid

Question 14

what is a solvent

Answer 14

the liquid DISSOLVING the substance

Question 15

what is solution

Answer 15

the mix of solvent and solute

Question 16

what is tonicity?

Answer 16

the ability of a soln to cause osmosis in a cell

Question 17

what is the concentration of human cell fluid?

Answer 17

300 mOsm/kg of water

Question 18

what does isotonic mean

Answer 18

soln has the same m of solute as body fluids

Question 19

what does HYPERtonic mean

Answer 19

soln has HIGHER m of solute as body fluids
therefore it could cause osmosis OUT of cell, becuase theres less water m
cell would shrink

Question 20

what does HYPOtonic mean

Answer 20

soln has LOWER m of solute than body fluids
therefore causes osmosis INTO cell because theres less water INSIDE the cell
cell would swell

Question 21

which ion has the higher m INSIDE the cell?

Answer 21

k is the only one that has higher m inside cel

na, cl, and ca all have ^ m outside the cell

Question 22

what is membrane potential?

Answer 22

theres a difference in charge bt outside and inside of the cell

• inside is more negative
• an electric potential separated by a cell membrane

Question 23

what is the resting membrane potential?

Answer 23

resting volts is -70mV inside the cell

• small amt of -ve ions (ANIONS) line the inner membrane
• small amt of +ve ions (CATIONS) line the outer membrane

Question 24

what is electrochemical equilibrium?

Answer 24

when there is a balance betweeen the chemical and electrical mgrads
-the potential is HOW MUCH is needed to balance it out

Question 25

what is the na/k pump?

Answer 25

• pumps OUT 3na and pumps IN 2k
• this makes the cell more -ve inside
• reqs atp (electrogenic pump) to move