Unit 2: Cell Structure and Function

Question 1

Ribosomes

Answer 1

make up rRNA, so involved in protein production

Question 2

Proof of common ancestry across life

Answer 2

ribosomes, they are present in all living things

Question 3

What does rough ER do?

Answer 3

has ribosomes; helps compartmentalize the cell; protein processing

Question 4

What does smooth ER do?

Answer 4

detoxification and lipid synthesis, sometimes lipid metabolism

Question 5

Golgi complex

Answer 5

membrane-bound, several flattened membrane sacs; packages proteins and lipids for transport

Question 6

Mitochondria structure and function

Answer 6

double membrane - smooth outside, folded inside. breaks down glucose into ATP to be used as energy

Question 7

Lysosome structure and function

Answer 7

membrane bound, have hydrolytic enzymes. digestion of outside material and as recycling; apoptosis

Question 8

Vacuole structure and function

Answer 8

membrane bound sac. store and release macromolecules and cell waste. in plants, it keeps water for turgor pressure

Question 9

Chloroplast structure and function

Answer 9

double outer membrane. in plants and photosynthetic algae.

Question 10

What does combined ER do?

Answer 10

mechanical support, protein synthesis on ribosomes, helps intracellular transport

Question 11

Why do cells have folding in inner membranes?

Answer 11

It increases surface area so more ATP can be made.

Question 12

What are inside chloroplasts?

Answer 12

thylakoids (discs) stacked into grana, and stroma (inner space)

Question 13

What makes up photosystems?

Answer 13

chlorophyll pigments and electron transport proteins inside membranes.

Question 14

Where does photosynthesis occur?

Answer 14

grana (stacks)

Question 15

What is the stroma?

Answer 15

fluid inside chloroplasts and outside thylakoids

Question 16

Where does carbon fixation happen?

Answer 16

stroma

Question 17

Where does the Krebs cycle happen?

Answer 17

mitochondrial matrix

Question 18

Where does electron transport and ATP synthesis occur?

Answer 18

inner mitochondrial membrane

Question 19

Compare large and small cells and their effectiveness

Answer 19

Small cells have higher surface area to volume ratio, so they are more efficient than large cells

Question 20

What happens to cells as they increase in size?

Answer 20

relative surface area decreases, and the smaller surface area cannot account for the much greater internal demands

Question 21

What can help with exchange in and out of the cell?

Answer 21

Structures, like membrane folds

Question 22

How can embedded proteins function in a hydrophobic and hydrophilic membrane?

Answer 22

They can be hydrophilic with charged, polar side groups (remember they’re proteins) or hydrophobic with nonpolar side groups.

Question 23

What is the structure of a membrane (fluid mosaic model)

Answer 23

made of the phospholipid bilayer embedded with proteins, steroids (cholesterol), glycoproteins, and glycolipids that are around the membrane

Question 24

What does the fluid mosaic model say about selective permeability?

Answer 24

It is caused by the membrane structure

Question 25

What molecules pass freely through the membrane?

Answer 25

small nonpolar molecules (N2, O2, CO2)

Question 26

What molecule types need channel or transport proteins?

Answer 26

hydrophilic substances (large polar molecules or ions)

Question 27

What is the difference between channel proteins and transport proteins?

Answer 27

Channel proteins are always passive; they just let large molecules or polar molecules in because they can't pass normally. Transport proteins are in active or passive transport; osmosis, facilitated diffusion, etc.

Question 28

What molecules can pass through the membrane in small amounts?

Answer 28

Polar uncharged molecules (H2O)

Question 29

What are cell walls made of?

Answer 29

Complex carbohydrates

Question 30

What is passive transport?

Answer 30

Movement of molecules from high to low concentration (with the concentration gradient) without using energy.

Question 31

What does passive transport usually move?

Answer 31

Materials and wastes (out)

Question 32

What is active transport?

Answer 32

Movement of molecules from low to high concentration (against concentration gradient) with the use of energy.

Question 33

Why do concentration gradients form?

Answer 33

Membranes are selectively permeable.

Question 34

What is the purpose of endocytosis and exocytosis?

Answer 34

Moving large molecules in and out of cell; takes energy

Question 35

Describe exocytosis

Answer 35

internal vesicles surround molecules and then move to the plasma membrane. The membrane and vesicles fuse and open so the molecules can leave the cell.

Question 36

Describe endocytosis

Answer 36

molecules gather outside the membrane, so the cell forms a new vesicle and lets the molecules in. The molecules are then moved to where they are needed in the cell.

Question 37

What are the two types of membrane proteins involved in facilitated diffusion of large charged polar molecules?

Answer 37

aquaporins (water), channel proteins (charged ions [Na/K])

Question 38

What happens to charge due to channel proteins?

Answer 38

Membranes become polarized

Question 39

Know water potential

Question 40

How are growth and homeostasis maintained?

Answer 40

Constant movement of molecules across cell membranes

Question 41

What is the purpose of osmoregulation?

Answer 41

It keeps a balance of water and lets organisms control their inner water potential compared to their environment.

Question 42

What is the purpose of membranes around organelles?

Answer 42

they compartmentalize inside the cell and help with enzymatic reactions.

Question 43

What is the purpose of internal membranes?

Answer 43

they minimize competing interactions and increase surface area for reactions (like mitochondria)

Question 44

Describe endosymbiosis

Answer 44

small prokaryote cell absorbed by large prokaryote. Became codependent and now we have eukaryotes.

Question 45

How do prokaryotes compare to eukaryotes regarding organelles?

Answer 45

Prokaryotes don't usually have organelles, but they do have regions of specialized structures and functions. Eukaryotic cells have internal membranes that split the cell into regions and also have organelles.