LECTURE 02

Question 1

What is the major difference between plants and animals at the cellular level

Answer 1

plants: cell wall, vacuole, chloroplast
Animals: Cholesterol

Question 2

What is the cell membrane made of

Answer 2

Made up of lipids, protein and carbohydrates

Question 3

What is the plasma membrane

Answer 3

a selective barrier that controls the movement of molecules from the inside and outside of the cell

Question 4

What is the endomembrane system

Answer 4

A system of membranes that include the nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, vesicles, and plasma membrane.

Question 5

What is the mitochondria/chloroplast

Answer 5

organelles used to harness energy and evolved from free-living prokaryotes

Question 6

What are the three main things in cell theory

Answer 6

All organisms are made of cells. The cell is the fundamental unit of life.
In general, cells come from pre-existing cells.

Question 7

What is the number of cells proportional to

Answer 7

the number of cells increase proportional to the size of the organism

Question 8

What can the human eye see up to in terms of cell size

Answer 8

We can see up to 100 um and can’t see most plant/animal cells as we need a microscope

Question 9

What is the phospholipid

Answer 9

The major lipid in the membrane

Question 10

Why are phospholipids amphipathic

Answer 10

they have both a hydrophilic head and hydrophobic tail

Question 11

What happens when the head of a phospholipid is large and bulky and only has one tail

Answer 11

They form Micelle

Question 12

What happens when the head of a phospholipid is small and has two tails

Answer 12

they form the bilayer

Question 13

What structure can the bilayer form

Answer 13

it forms an enclosed structure called the liposome

Question 14

What is cholesterol and how does it work

Answer 14

an important component in the animal cell that influences membrane fluidity by forming strong interactions with phospholipids by acting as a buffer

Question 15

What happens at high temps for cholesterol

Answer 15

they affect the tail and reduce fluidity

Question 16

what happens at low temps for cholesterol

Answer 16

they prevent lipids from packing too tight together

Question 17

What is the receptor for

Answer 17

they allow the cell to receive signals from the environment

Question 18

What do enzymes do

Answer 18

they catalyze chemical reactions

Question 19

What is the anchor for

Answer 19

they attach to other protein to help maintain cell structure/shape

Question 20

What is a integral protein

Answer 20

protein that are permanently on the cell membrane (can’t be removed)

Question 21

What is a peripheral membrane protein

Answer 21

protein that are temporarily on the lipid-bilayer or integral protein

Question 22

How to peripheral membrane protein stay on other protein

Answer 22

Using weak non-covalent interactions

Question 23

What do transporter do and what type of protein is it

Answer 23

they have the important function of moving ions/molecules across the membrane and they are integral proteins

Question 24

How does the plasma membrane determine what moves across it

Answer 24

The plasma membrane is selective permeable (selects what moves across it)

Question 25

What is the simplest movement across the membrane

Answer 25

Passive transport

Question 26

How does passive transport work

Answer 26

It works through diffusion which is the movement of molecules from high concentration to low concentration the opposite can occur. No energy required

Question 27

What it the process for moving large molecules across the plasma membrane

Answer 27

Facilitated diffusion

Question 28

How does facilitated diffusion work

Answer 28

it works through proteins called channels and carriers which help move across the plasma membrane

Question 29

What is the process name for diffusion of water

Answer 29

Osmosis

Question 30

What are the four types of osmosis

Answer 30

Hypertonic- water moves from cell to outside Isotonic - outside and inside have the same concentration Hypotonic- water moves from outside to inside cell very hypotonic - too much water moves inside cell and cell bursts

Question 31

Why does the cell wall not burst during osmosis

Answer 31

the cell wall can't burst as it can take in a lot of water

Question 32

What is the force exerted by water against the cell wall

Answer 32

turgor pressure

Question 33

What is active transport

Answer 33

transport where it moves from low to high concentration and needs energy from ATP

Question 34

What are the two types of active transport

Answer 34

primary and secondary active transport

Question 35

What occurs in primary active transport (how does is use energy)

Answer 35

transport of sodium and potassium against concentration gradient. Uses energy directly

Question 36

What occurs in secondary active transport

Answer 36

primary active transport pumps protein across cell membrane and creates a proton concentration -> antiporters use protons to move molecules against gradient

Question 37

What is the process of exocytosis

Answer 37

vesicles are budded off of the endomembrane system and fuses with the membrane and gives content from the membrane to extracellular space

Question 38

What is the nucleus

Answer 38

stores cell dna

Question 39

Nuclear envelope

Answer 39

it defines the boundary's of the nucleus

Question 40

Nuclear pores

Answer 40

They help nucleus communicate with cells

Question 41

What is Er

Answer 41

Its a large organelle that produces lipid/protein for uses inside/outside the cell

Question 42

What is the rough Er

Answer 42

associated with ribosomes it synthesizes proteins using the ribosomes

Question 43

What is the smooth Er

Answer 43

it has no ribosomes and used for lipid synthesis

Question 44

What does the Golgi apparatus do

Answer 44

modifies protein/lipids produced in Er and sorts them as they go to final destination

Question 45

What does the lysosomes do

Answer 45

they are relied on for protein, lipid, carbohydrates, and acid degradation

Question 46

mitochondria/chloroplast

Answer 46

can duplicated themselves believed to be bacteria/prokaryote that was captured by eukaryote (lived in cells)