Unit 4

Question 1

What are the different types of Cell Communications? (4)

Answer 1

1. Direct cell-cell communications
2. Paracrine
3. Endocrine
4. Autocrine

Question 2

How does direct cell-cell communication work?

Answer 2

A cell touches another cell, the protein link

the gap is called

animal = gap junction
plant = plasmodesmata

Question 3

Paracrine?

Answer 3

Short Distance communication

Synaptic = use of neurons

Question 4

Endocrine?

Answer 4

Long distance communications

Question 5

Autocrine

Answer 5

Receptor bind to its own Ligand

Question 6

What are the three types of membrane CELL SURFACE receptors?

Answer 6

1. Ligand - gated ion channels
2. G-protein coupled receptors
3. Enzyme linked receptors

Question 7

Ligand gated ion channels

Answer 7

The receptor binds to the ligand, opening up a ion channel

Question 8

Enzyme linked receptors

Answer 8

An enzyme binds to its substrate, setting off a chain of reactions in the cell

Question 9

G-Protein

Answer 9

Review chart

Question 10

Primary Messenger

Answer 10

A ligand that binds to a receptor on the outside of the cell, setting off a chain of reactions

Question 11

Secondary Messenger

Answer 11

the ligand that is set off by the primary messenger, making the game of telephone happen

Question 12

Gain of Function

Answer 12

A mutation in the cell which makes the reaction occur without the receptor binding to the ligand

Question 13

Loss of Function

Answer 13

A mutation in the cell which makes the reaction NOT occur even when the receptor binds to the ligand

Question 14

Homeostatis

Answer 14

Tendency to go to stable internal enviorment

Question 15

Positive Feedback Loop

Answer 15

Amplifies stimulus

Question 16

Negative Feedback Loop (4 parts)

Answer 16

Stimulus - thing happens
sensor - thing is noticed
control - reduce that thing
effector - back to normal

Question 17

Set Point

Answer 17

The stable target value

Question 18

Stimulus

Answer 18

Trigger for feedback / “cue”

Question 19

decondensed

Answer 19

“stringy”

Question 20

condensed

Answer 20

not stringy, compact

Question 21

What’s wrong with cancer cells? (4)

Answer 21

1. Constantly reproduce cells
2. Cells have damaged DNA
3. They don’t die
4. They spread

Question 22

autosomes

Answer 22

Non-sex chromosomes

Question 23

signal relay pathway

Answer 23

game of telephone with ligand and receptors

Question 24

what do we mean by ligand is turned on?

Answer 24

Phosphorylation - ADP is converted to ATP with the help of enzyme Kinase

Question 25

Cell Cycle

Answer 25

The Cell must reproduce, so it goes through multiple phases in order to do this These phases are called 1. Interphase 2. Mitosis

Question 26

Interphase

Answer 26

The interphase is the phase in the cell cycle where the DNA is duplicated and where it grows It is made up of 1. G-one (grows) 2. S phase (chromatin grows and the DNA duplicates) 3. G two (grows some more)

Question 27

Mitosis

Answer 27

Mitosis goes through many phases in order to ultimately split the cell into two, identical daughter cells

Question 28

Taxis

Answer 28

movement of an organism in response to a stimulus

Question 29

chemotaxis

Answer 29

a type of taxis that responses to a CHEMICAL stimulus

Question 30

Signal transduction

Answer 30

external signal is transmitted to the inside of the cell

Question 31

What are the three steps for signal transduction?

Answer 31

1. A signaling molecule binding to a specific receptor 2. activation of signal transduction pathway 3. production of cellular response

Question 32

salinity

Answer 32

containing salts or mg

Question 33

centromere

Answer 33

the place where the sister chromatids are linked

Question 34

apoptosis

Answer 34

programed for death

Question 35

oncogenes

Answer 35

mutated cancer cells

Question 36

tumor suppressor genes

Answer 36

produce proteins that prevent normal cells turning into cancer cells

Question 37

kinetochore

Answer 37

the place where the spindle attaches during prophase

Question 38

cleavage furrow

Answer 38

the part where the cell is split during telophase for animal cells

Question 39

cell plate

Answer 39

the part where the cell is split during telophase for plants

Question 40

disjunction

Answer 40

the process where chromosomes separate and move apart towards opposite poles of a cell during cell division

Question 41

quorum sensing

Answer 41

a process of cell-to-cell communication that allows bacteria to sense their population density and adjust their gene expression

Question 42

juxtacrince signaling

Answer 42

direct cell to cell communication