Unit 4

Question 1

signal transduction

Answer 1

process of a signal activating a certain response in another or the same cell

Question 2

autocrine signal

Answer 2

chemical messages that affect the same cell they originated from

Question 3

paracrine signal

Answer 3

chemical messages that affect local cells

Question 4

endocrine signal

Answer 4

chemical messages that target cells over a long distance by traveling through the bloodstream

Question 5

cell to cell contact

Answer 5

sending and receiving important information through direct contact (ex: signal to tell nearby cells to stop dividing)

Question 6

local regulators

Answer 6

signals over small distances (ex: neurotransmitters)

Question 7

endocrine system

Answer 7

coordinated activity of the body by releasing hormones that circulate blood stream to organs and tissues across the body (ex: pancreas, insulin and glucagon)

Question 8

reception

Answer 8

protein receives signal (could be ligand or physical change)

Question 9

transduction

Answer 9

transmission of signal throughout the cell through secondary messengers and proteins

Question 10

response

Answer 10

action carried out because of the signal, depends on what the signal is, what kind of cell it is, and the external environment

Question 11

what occurs when the protein binds to the ligand?

Answer 11

a conformational change that travels through hydrophobic part of membrane and into the cell (this starts transduction)

Question 12

phosphorylation cascade

Answer 12

starts with the creation of a second messenger that activates thousands of enzymes throughout the cell

Question 13

secondary messenger

Answer 13

spreads signal throughout the cell and activates enzymes leading to cellular response, non protein and water-soluble

Question 14

what are the two types of receptors

Answer 14

membrane proteins and intercelluar proteins

Question 15

g-protein coupled receptors (GPCR)

Answer 15

membrane bound protein that goes through membrane seven times and start the phosphorylation cascade

Question 16

what is the function of protein kinases?

Answer 16

they transfer phosphates from ATP to a proteins to activate it

Question 17

protein phosphatases

Answer 17

enzymes that remove phosphate from a protein to deactivate it

Question 18

dimerization

Answer 18

when a growth factor binds to a cellular receptor domain

Question 19

competitive inhibitors

Answer 19

block active site so substrate can’t enter

Question 20

noncompetitive inhibitors

Answer 20

bind to another spot but prevent catalysis

Question 21

uncompetitive inhibitors

Answer 21

bind to substrate enzyme complex

Question 22

activators

Answer 22

activate pathway

Question 23

interphase

Answer 23

the chromosomes duplicate and two centrosoles will organize the spindle fibers in preparation of chromosome seperation

Question 24

prophase

Answer 24

centrosoles migrate to opposite poles of cell, the nuclear envelope begins to break down and seek out the centrosomes of each chromosome

Question 25

metaphase

Answer 25

chromosomes line up on metaphase plate where chromatids begin to separate

Question 26

anaphase

Answer 26

chromatids fully seperate into individual chromosomes and chomosomes are pulles to poles of cell, the chromosomes don't rip apart, they walk away from each other

Question 27

telophase

Answer 27

nuclear envelope reforms around each nucleus and cleavage furrow begins to form and starts to pinch cell into two

Question 28

cytokenesis

Answer 28

full separation of cells, not a part of mitosis

Question 29

positive feedback mechanisms

Answer 29

process that starts or continues a cellular process

Question 30

negative feedback mechanisms

Answer 30

process that stops or slows a cellular process

Question 31

negative feedback system

Answer 31

operate to maintain a specific setpoint (ex: homeostasis)

Question 32

positive feedback system

Answer 32

employed when a process needs to proceed a certain threshold so a greater action can be employed (ex: childbirth)

Question 33

S Phase

Answer 33

synthesis phase, new strands of DNA are synthesized by DNA polymerase, DNA is being replicated

Question 34

G1 Phase

Answer 34

cell metabolizes energy and creates new protiens/lipids, growth

Question 35

G2 Phase

Answer 35

cell continues growing, replicates important organelles, and replicates other cellular components in preparation for division

Question 36

G0

Answer 36

cell isn't working to grow or divide, just functioning (ex: nerve cells)

Question 37

Mitosis

Answer 37

cell separates DNA into two cells and process restarts

Question 38

binary fission

Answer 38

used by bacteria in order to divide

Question 39

meiosis

Answer 39

sexual reproduction, gametes must duplicate

Question 40

G1 checkpoint

Answer 40

cell checks if size is appropriate, if there is enough nutrients for both daughter cells, and checks DNA to make sure there there is no damage. If cell fails then it goes into G0, signals activate proteins that sens cascade

Question 41

G2 checkpoint

Answer 41

DNA replication has completed and checked for damage, if it passes the test it goes into mitosis and if it doesn't then APOPTOSIS CELL DEATH. if the cell is okay then there is a chemical release to start mitosis.

Question 42

M checkpoint

Answer 42

during metaphase, ensures that chromosomes are equally divided and both cells have a full genetic code

Question 43

chromatin

Answer 43

loosely coiled/compacted (interphase = chromatin)

Question 44

chromosome

Answer 44

tightly coiled chromatins

Question 45

internal regulators

Answer 45

Cyclins, CDKs, and checkpoints

Question 46

external regulators

Answer 46

growth factor, density dependent, anchor dependent

Question 47

growth factor

Answer 47

protein that stimulates cells to divide (can be autocrine)

Question 48

density dependent

Answer 48

crowded cells stop dividing in healthy tissue

Question 49

anchorage dependent

Answer 49

healthy cells must be attached to a substratum to divide

Question 50

pro-oncogenes code

Answer 50

code for proteins that stimulates normal cell growth and division "the gas"

Question 51

oncogenes

Answer 51

cancer causing genes

Question 52

2 types of genes associated with cancer genetics

Answer 52

tumor suppressor genes and pro-oncogenes

Question 53

tumor suppressor genes

Answer 53

encode proteins that inhibit abnormal cell divisions, "the break"

Question 54

p53 gene

Answer 54

encodes of tumor suppressor gene, "guardian angel", it's the spell check of DNA and pauses to see if cell should correct mistakes or apoptosis.

Question 55

cyclins

Answer 55

group of related proteins that progress the cell cycle, they vary in concentration based on cell's phase

Question 56

CDK

Answer 56

enzymes involved in cell cycle regulation that require cyclin binding for activation, they phosphorylate substrates and promote certain cell activities.