Test 2-diffusion, Endomembrane System

Question 1

Why is a larger SA to V ratio more efficient, are smaller or bigger cells better

Answer 1

Smaller ratio requires more nutrients and creates more waste, but takes longer for the waste to leave and nutrient to get in, smaller cells are better because they have a larger ratio

Question 2

What is the cytoplasm composed of

Answer 2

Composed of water, salts, and dissolved organic molecules

Question 3

Whatre integral and peripheral proteins

Answer 3

Integral goes through both layers of bilayer, peripheral are only found on the top or bottom of the bilayer

Question 4

What do carbohydrates do

Answer 4

Carbohydrate chains attach to form glycolipids and glycoproteins

Question 5

What do glycoproteins do

Answer 5

Functions in cell recognition, cell signaling

Question 6

What do glycolipids do

Answer 6

Maintain stability of cell membrane

Question 7

What do channel proteins do

Answer 7

Give a path for molecules that cannot enter alone in the plasma membrane

Question 8

What do carrier proteins do

Answer 8

Help carry molecules past the bilayer

Question 9

What do receptor proteins do

Answer 9

Recieve molecules, such as hormones

Question 10

What do enzymatic proteins do

Answer 10

Proteins that are also enzymes, catalyzing chemical reactions

Question 11

What does cholesterol do, where is it found

Answer 11

Found embedded in the bilayer (integral), helps stabilize and give shape

Question 12

What can pass the plasma membrane easily

Answer 12

Small, uncharged molecules (O2, CO2)

Question 13

What cannot pass the membrane easily

Answer 13

Large proteins and tiny, polar, or charged molecules

Question 14

What is simple diffusion

Answer 14

Passive transport that doesnt require the help from proteins

Question 15

What is facilitated diffusion

Answer 15

Passive transport that requires protein carriers/channels specific to the transported substance

Question 16

Do all carriers and channels require ATP

Answer 16

Some do, some dont

Question 17

What is passive transport and diffusion

Answer 17

Another name for diffusion, particles going from high to low concentration

Question 18

What is osmosis

Answer 18

Diffusion of water from high to low concentrations

Question 19

How does the sodium potassium pump work, where is it active

Answer 19

Active in all animal cells
A carrier protein that moves sodium ions to the outside of the cell and potassium ions to the inside

Question 20

What is a pump

Answer 20

A carrier protein required in active transport

Question 21

What does it mean for the sodium potassium pump to exist in two conformations

Answer 21

It opens on both sides

Question 22

When is exocytosis or endocytosis used

Answer 22

Generally for transporting much larger molecules/ many molecules at once

Question 23

What is exocytosis, give an example

Answer 23

Vesicles fuse with plasma membrane for secretion
Ex. Pancreas calls release digestive enzymes
Insulin is secreted due to rising blood glucose levels

Question 24

What is endocytosis, what are the three types and examples of them

Answer 24

Cells take in substance by forming a vesicle around it
1. Phagocytosis: taking in large particles, like white blood cells consuming antigens
2. Pinocytosis: taking in small particles (but can do so in bulk), used in kidneys and intestines
Receptor mediated endocytosis: involves specific particles like hormones and nutrients through receptor binding
Used in placentas

Question 25

What is the pressure that helps with homeostasis of water, how is it formed

Answer 25

Osmotic pressure is the pressure that builds up in a system due to osmosis
If enough, can prevent excess amounts of water to enter, maintaining homeostasis

Question 26

What happens to a plant or animal cell in a hypotonic solution?

Answer 26

Plant: swells and expands
Animal cells swell and possibly burst (lyse)

Question 27

Why do plant cells not burst in hypotonic solutions?

Answer 27

The cell wall is rigid and resists the expansion of the cell membrane pushing against the wall by increaed turgor pressure

Question 28

What happens to plant and animal cells in hypertonic solutions

Answer 28

Plant: undergo plasmolysis
Animal cells: crenation

Question 29

What is plasmolysis

Answer 29

Cytoplasm shrinks, membrane separates from the cell wall

Question 30

What is the endomembrane system

Answer 30

A group of interconnected organelles in eukaroytic cells that work together to modify, package, and transport lipids and proteins

Question 31

Whatre carrier proteins and how are they different from channel proteins

Answer 31

Proteins that bind to a specific molecule and undergo a conformational change, releasing the molecule on the other side of the membrane afterwards
Very specific to the transported molecule (more specific than channels)

Question 32

What does the nuclear envelope do, where is it

Answer 32

Surrounds the nucleus and is connected to RER
Has pores that regulate exchange of genetic materials between the nucleus and the cytoplasm
Allows mrna to travel to RER

Question 33

What does the RER do and make, where do they send the created molecule to

Answer 33

Synthesizes proteins, sends them to golgi body through transport vesicles

Question 34

What does the SER do, where does it send the created molecule to

Answer 34

It makes lipids and detoxifies substances
Sends to golgi body through transport vesicles

Question 35

What does the golgi body do, what does it make

Answer 35

Makes transport vesicles and secretory vesicles
Receives proteins and lipids, modifying and packaging them into vesicles

Question 36

How are materials sent to lysosomes

Answer 36

Sent from the golgi body or by endocytosis

Question 37

Whatre the three types of vesicles and where are they made

Answer 37

Transport vesicles used around the cell, made by golgi body and ER
Secretory vesicles used outside the cell, made by golgi body
incoming vesicles used inside the cell, made by cell membrane