Cell Biology

Question 1

All cells have too

Answer 1

• expel waist and bring in nutrients
• keep internal environment different then external
• Make proteins
• Divide and replicated

Question 2

What are some characteristics of the plasma membrane

Answer 2

• selective barrier: allows important materials in but it others
• general structure: double layer of phospholipids
• Contributions from internal membrane system
• connections to cytoskeleton

Question 3

What are integral proteins?

Answer 3

Wishing the bilayer of a cell, non polar R groups interact with the fatty acids in the hydrophobic regions

Question 4

What are peripheral proteins?

Answer 4

Attached to the surface, joining cells and recognition of self and non self

Question 5

What are he functions of enzymes?

Answer 5

Catalyze reactions

Binding sites exposed to accept substrates

Question 6

What are the functions of transports

Answer 6

• move solutes, other molecules
• hydrophilic channels or shuttles
• some use atp

Question 7

How often do phospholipids move side to side vs up and down?

Answer 7

Side to side - 10^7 per second

Up down once a month

Question 8

How does cholesterol stabilize membrane fluidity?

Answer 8

Site in between phospholipids and reduces movement (prevents too much fluidity) and prevents tight packing ( prevents to much solidity)

Question 9

Which fatty acid causes a membrane to be more fluid/ not solid

Answer 9

Unsaturated - more fluid

Saturated - more solid

Question 10

Cell membrane is permeable to what?

Answer 10

Non polar molecules and opposite

Question 11

What is the size of a cell and organelles

Answer 11

Cell 1-100um

Organelles ~1 um

Question 12

As volume decreases what happens to size in a cell

Answer 12

Size increases

Question 13

What are Protists

Answer 13

Unicellular eukaryotes the first eukaryotes to evolve

Question 14

From oldest to newest name the major things that happened for development of life on earth

Answer 14

• prokaryotes
• atmospheric oxygen
• single called eukaryotes
• multicellular eukaryotes
• animals
• colonization of land

Question 15

What cells evolved first and when

Answer 15

Prokaryotic cells 3.5 billion years ago

Question 16

What caused the oxygen revolution?

Answer 16

Cell membranes specialized for photosynthesis in some of the first cells which produced oxygen and caused some cells to go extinct that couldn’t handle the oxygen

Question 17

What is the cell membrane composed of?

Answer 17

Phospholipid bilayer (fatty acids and polar heads that interact with each other (yellow and purple model))

Question 18

How do cells react to temperature change?

Answer 18

Change Their phosphlypid composition- if temperate is increased the cell will increase % of saturated fatty acids in membrane

Question 19

Membrane bound organelles are present in what

Answer 19

Eukaryotes only