test 3

Question 1

what is juxtacrine?

Answer 1

direct contact signalling

Question 2

what happens in a gap junction?

Answer 2

they swap cytosol

Question 3

what is autocrine?

Answer 3

secreting cell and target cell are the same

Question 4

what is paracrine?

Answer 4

cell produces a signal that affects nearby cells

Question 5

what is synpatic signalling?

Answer 5

similar to paracrine, only occurs at the synapse of two cells

Question 6

what is endocrine?

Answer 6

long distance signalling

Question 7

what are the 3 processes of signals?

Answer 7

reception, transduction, response.

Question 8

what happens during reception?

Answer 8

target cells (ligands) detect signalling molecules. the cell will repsond to a ligand depending on the receptors it has. key and lock

Question 9

what is a extracelluar receptor?

Answer 9

transmembrane proteins in the plasma membrane

Question 10

what are some examples of intracelluar receptors?

Answer 10

cytoplasm, nucleus, intracelluar membranes

Question 11

what happens during transduction?

Answer 11

once bound to a ligand the receptor will change shape . the signal cascades to different proteins is often amplified.

Question 12

what are protein kinases?

Answer 12

they transfer phosphates from atp to protein (phosphorylation)

Question 13

what are protein phosphatases?

Answer 13

they rapidly turn proteins off

Question 14

what turns proteins on?

Answer 14

phosphorylation

Question 15

what is the process where they remove phosphates?

Answer 15

dephosphorylation

Question 16

what are secondary messengers?

Answer 16

small non-protein, water soluable molecules or ions, can diffuse quickly

Question 17

what is adenlyl cyclase?

Answer 17

an enzyme in the plasma membrane and creates cAMP

Question 18

what does cAMP activate?

Answer 18

protein kinase A, which phosphorolizes other proteins and amps the signal

Question 19

phosphodiesterase inactivates what?

Answer 19

cAMP message

Question 20

why is calcium a good secondary messenger?

Answer 20

concentration differences makes it highly rapid and regulated

Question 21

where does the output response occur?

Answer 21

cytoplasm or nucleus

Question 22

what are some common cellular responses?

Answer 22

activate and enzyme, synthesis of proteins by synthesizing mRNA

Question 23

what are the 4 aspects of signal regulation to consider?

Answer 23

amplification of the signal, specificity of the response, efficiency of the response, termination of the signal.

Question 24

what are scaffolding proteins?

Answer 24

they bring signaling molecules together, they increase signal efficiency and can activate relay proteins

Question 25

why would receptors want to stop receiving signals?

Answer 25

if a ligand fails, fewer receptors will be activated, unbound receptors fall into an inactive state.

Question 26

what is the most common receptor?

Answer 26

g-protein coupled receptors

Question 27

what happens to a g-protein in an inactive state?

Answer 27

g-proteins are attached to the GPCR and bound to GDP

Question 28

what are GDP and GTP?

Answer 28

guanine nucleotides

Question 29

what happens after a g-protein is bound to GTP?

Answer 29

the g-protein leaves the GPCR and interacts with enzymes

Question 30

What is norepinephrine?

Answer 30

a neurotransmitter, affects the fight or flight response

Question 31

what are some repsonses to norepinephrine?

Answer 31

increased bladder control, pupil dilation, increases blood pressure

Question 32

what are receptor tyrosine kinases?

Answer 32

they are membrane receptors, they catalyze the transfer of phosphates to tyrosine residues, can trigger multiple tranduction pathways

Question 33

what is one of the most known causes of cancer?

Answer 33

RTK dysfunction

Question 34

what is a ligand-gated ion channel receptor?

Answer 34

a ligand makes the receptor open like a gate, highly selective for specific ions

Question 35

what receptors do small hydrophobic molecules bind to?

Answer 35

intracellular receptors

Question 36

what is apoptosis?

Answer 36

programmed cell death

Question 37

how is apoptosis triggered?

Answer 37

by signals that activate a cascade of "suicide" proteins

Question 38

what engulfs apoptoic blebs?

Answer 38

scavenger cells

Question 39

what are caspases?

Answer 39

types of proteases that degrade proteins

Question 40

what is the chromosome theory of inheritance?

Answer 40

specific genes are associated with specific chromosomes

Question 41

what is a loci

Answer 41

a gene's location on a chromosome

Question 42

what are alleles?

Answer 42

alternate variants in a gene

Question 43

what is polyploidy?

Answer 43

two complete sets of chromosomes

Question 44

what is aneuploidy?

Answer 44

uneven seperation of one chromosome leading to offspring with an abnormal chromosome number

Question 45

what is monosomic?

Answer 45

zygote has only one copy of a particular chromosome

Question 46

what is trisomic?

Answer 46

zygote has three copies of a particular chromosome

Question 47

what is genomic imprinting?

Answer 47

certain genes will be silenced depending on which parent passes them on

Question 48

how are cytoplasmic genes inherited?

Answer 48

maternally because the zygote's cytoplasm comes from the egg

Question 49

what are extranuclear or cytoplasmic genes?

Answer 49

small circular DNA molecules in mitochondria, chloroplasts, and other plant plastids

Question 50

What are the 3 main purposes of cell division?

Answer 50

reproduction, growth and development, tissue renewal/repair

Question 51

what is a genome?

Answer 51

all the DNA in a cell

Question 52

what are packaged DNA molecules in a cell?

Answer 52

chromosome

Question 53

how are chromatids attached?

Answer 53

cohesins

Question 54

what happens during interphase?

Answer 54

cell growth and copying of chromosomes in preparation for cell division

Question 55

what is the mitotic phase?

Answer 55

consists of both mitosis and cytokinesis

Question 56

what phase do chromosomes duplicate?

Answer 56

S Phase

Question 57

what does the mitotic spindle do?

Answer 57

controls chromosome movement

Question 58

what happens during prophase?

Answer 58

chromatin fibers become tightly coiled, mitotic spindles start to form

Question 59

what happens during prometaphase?

Answer 59

nuclear envelope fragments, kineticores, a protein structure, connects to centromeres

Question 60

what happens in plant cells during cytokinesis?

Answer 60

a cell plate forms

Question 61

how do prokaryotes divide?

Answer 61

binary fission

Question 62

what do cyclins and cyclin-dependent kinases (cdks) do?

Answer 62

regulate the cell cycle

Question 63

what is anchorage dependence?

Answer 63

cells require a surface for division

Question 64

what is density-dependent inhibition?

Answer 64

cells form a single layer

Question 65

what are benign tumors?

Answer 65

form lumps that stay in their original location

Question 66

what are malignant tumors?

Answer 66

invade surrounding tissues and can metastasize moving to other areas of the body

Question 67

what is the transmission of traits from one generation to the next

Answer 67

heredity

Question 68

crossover occurs are x-shaped sites called?

Answer 68

chiasmata

Question 69

what is independent assortment?

Answer 69

homologous pairs of chromosomes orient randomly at metaphase 1 of meiosis

Question 70

what is random fertilization

Answer 70

any sperm can fuse with any egg

Question 71

what does antiparallel mean?

Answer 71

their subunits run in opposite directions

Question 72

what is a conservative model?

Answer 72

retain the parental and synthesize a new molecule

Question 73

what is a semiconservative model?

Answer 73

each daughter will retain parent strand with a new strand

Question 74

what is a dispersive model?

Answer 74

two molecules with parental and new DNA interspersed within each