Unit 4

Question 1

Cell-cell signaling is important for the ________ and ________ of cells.

Answer 1

function/survival

Question 2

Cell-cell signaling involves:

Answer 2

transmission of a signal from a sending cell to a receiving cell.

Question 3

2 modes of cell communication are:

Answer 3

Direct contact and local/long-distance signaling

Question 4

Direct contact has cells communicate by:

Answer 4

Cell-cell contact

Question 5

2 types of direct contact:

Answer 5

Direct channels of communication and cell-cell recognition

Question 6

2 types of local signaling:

Answer 6

Paracrine signaling and autocrine signaling

Question 7

Paracrine Signaling

Answer 7

Signaling cells release chemical messages to travel a short distance to a nearby target cell

Question 8

Autocrine Signaling

Answer 8

Sends chemical messages to itself to regulate self through +/- feedback

Question 9

Long Distance Signaling

Answer 9

Hormones are sent to produce response in target cells that are far from signaling cell

Question 10

How do plants use long-distance signaling?

Answer 10

Releases hormones into vascular tissue (xylem and phloem) or air

Question 11

How do animals use long-distance signaling?

Answer 11

Specialized cells release hormones into the circulatory system to reach target cells.

Question 12

What channels do animals have for direct contact?

Answer 12

Gap Junctions (connexons)

Question 13

What channels do plants have for direct contact?

Answer 13

Plasmodesmata

Question 14

Cell signaling is an interaction between a ______ and ________.

Answer 14

ligand/receptor

Question 15

What is a positive feedback?

Answer 15

An amplification in a function in order to stabilize a system.

Question 16

What is negative feedback?

Answer 16

A decrease in a function in order to stabilize a system.

Question 17

What’s a ligand?

Answer 17

A peptide/small molecule sent as a chemical messenger to receptors.

Question 18

What’s a receptor?

Answer 18

Proteins that recognize and bind to ligands.

Question 19

Where can receptors be found?

Answer 19

In the plasma membrane or inside the cell.

Question 20

What do cell-surface receptors bind to?

Answer 20

Polar and large ligands

Question 21

What part of a surface receptor interacts with ligands?

Answer 21

Ligand-binding domain

Question 22

What part of a surface receptor spans the plasma membrane?

Answer 22

Transmembrane Domain

Question 23

What part of a surface receptor transmits a signal into the cell?

Answer 23

Intracellular domain

Question 24

What kinds of ligands can intracellular receptors bind with?

Answer 24

Small hydrophobic molecules
(steroid hormones or gasses)

Question 25

Where can intracellular receptors be found?

Answer 25

Cytoplasm or nucleus

Question 26

Process of DNA to m(essenger)RNA

Answer 26

Transcription

Question 27

Process of mRNA to protein

Answer 27

Translation

Question 28

What part of a intracellular receptor interacts with the ligand?

Answer 28

Ligand-binding domain

Question 29

What part of an intracellular receptor interacts with regions of target genes?

Answer 29

DNA-binding domain

Question 30

Three Stages of Cell-Cell signalling

Answer 30

1. Reception 2, Transduction 3. Response

Question 31

Reception

Answer 31

Ligand binds to receptor

Question 32

Transduction

Answer 32

Extracellular signal turns into an intracellular response

Question 33

Response

Answer 33

Something in the cell process is changed by the signal.

Question 34

Transduction in cell-surface receptors:

Answer 34

Enzymes and second messengers relay and amplify signal through a signaling cascade

Question 35

Protein kinases

Answer 35

Enzyme that turns on proteins by giving a phosphate group

Question 36

Protein phosphatases

Answer 36

Enzyme that turns off proteins by taking away a phosphate group

Question 37

What counts as second messengers for the ligand's first message?

Answer 37

Small, non-protein molecules and ions in the cell

Question 38

What happens when a ligand binds to a G protein receptor (GPCRs)?

Answer 38

The G protein is activated since GTP had been allowed to bind.

Question 39

How does a cellular response occur from an effector?

Answer 39

Effector binds with a G protein and produces second messengers.

Question 40

What are ligand gated ion channels?

Answer 40

A type of cell-surface receptor that acts as a "gate" for ions. Only turns on when ligands bind to it.

Question 41

Cell Cycle:

Answer 41

Life of a cell from formation to division

Question 42

What forms nucleosomes

Answer 42

DNA wrapped around histomes

Question 43

Chromatin

Answer 43

Nucleosomes wound into string

Question 44

Chromosome

Answer 44

Condensed chromatins

Question 45

SIster Chromatids

Answer 45

Duplicated DNA information

Question 46

Kinetochore

Answer 46

Links sister chromatids to mitotic spindles

Question 47

Centromere

Answer 47

Region that sister chromatids are most connected

Question 48

Homologous Chromosomes

Answer 48

2 chromosomes (1 from mom/dad) that have same info, length, and centromere position

Question 49

Somatic Cells

Answer 49

Body cells that have 2 sets of chromosomes from each parent and divides by mitosis - 2n = 46

Question 50

Gametes

Answer 50

Reproductive cells that only have 1 set and divides by meiosis

Question 51

Prokaryotes regarding genome

Answer 51

singular and circular DNA

Question 52

Eukaryotes regarding genome

Answer 52

1 or more linear chromosomes

Question 53

During the cell cycle, a cell spends most of its life in __________.

Answer 53

Interphase

Question 54

Interphase consists of _________.

Answer 54

G1, S, G2

Question 55

G1

Answer 55

Normal cell functions and duplicates organelles

Question 56

S (synthesis):

Answer 56

DNA duplicates from chromatin into 2 sister chromatids

Question 57

G2

Answer 57

Protein, ATP and centrosomes produced

Question 58

Mitosis

Answer 58

Nucleus divides and results in 2 diploid cells

Question 59

Cytokinesis

Answer 59

Cytoplasm divides

Question 60

Phases of mitosis

Answer 60

Early/late prophase, Metaphase, Anaphase, Telophase

Question 61

Early Prophase (4 key events)

Answer 61

-Chromosomes condense -Nucleoli disappear -Mitotic spindle begins to form -Centrosomes move away from each other

Question 62

Late Prophase (prometaphase) (3 key events)

Answer 62

Chromosomes still condensing, nuclear envelope fully gone, and some mitotic spindles able to attach to kinetochores

Question 63

Metaphase

Answer 63

Centrosomes at opposite poles, microtubules attach to kinetochores, chromosomes lined up (metaphase plate)

Question 64

Anaphase

Answer 64

Sister chromatids separate towards opposite ends and cell elongates

Question 65

Telophase

Answer 65

Mitotic spindles breakdown & 2 daughter nuclei form.

Question 66

Animal cytokinesis

Answer 66

Cleavage furrow appears due to contractile ring

Question 67

Plant cytokinesis

Answer 67

vesicles produced by the Golgi travel to the middle of the cell and form a cell plate

Question 68

What does the G1/S checkpoint check for?

Answer 68

Cell size, growth factors, and DNA damage

Question 69

What does the G2/M checkpoint check for?

Answer 69

DNA replication completion and damage

Question 70

What cells can stay in G0 phase?

Answer 70

Muscle and nerve cells

Question 71

Cells can reenter the cell cycle from G0: T or F

Answer 71

True

Question 72

What happens if there's a stop signal at the G2 checkpoint?

Answer 72

Damage repair; if damage can't be repaired, cells undergo apoptosis (cell death)

Question 73

What does the M (spindle) checkpoint check for?

Answer 73

Mitotic spindle attachment to kinetochore

Question 74

Anchorage Dependence

Answer 74

Cells need to be attached to other cells in order to divide.

Question 75

Contact (or density) inhibition

Answer 75

Cells stop growing if they don't have enough space to divide

Question 76

Normal cells become cancerous through ___ _________.

Answer 76

DNA mutations

Question 77

Cancer cells

Answer 77

Doesn't follow checkpoints, divides infinitely, and evades apoptosis

Question 78

Abnormal cells form into a tissue called a _____.

Answer 78

Tumor

Question 79

Benign tumor

Answer 79

Stays in one place and does not spread

Question 80

Malignant tumor

Answer 80

Loses anchorage dependence and spreads

Question 81

Metastasis

Answer 81

Cells separate from body and spread to other parts of the body

Question 82

Type of cyclin during G1 and S

Answer 82

Cyclin E

Question 83

Type of cyclin during G2

Answer 83

Cyclin A

Question 84

Type of cyclin during Mitosis

Answer 84

Cyclin B

Question 85

Internal control system of cell cycle consists of:

Answer 85

Cyclin and cyclin-dependent kinase (CDK)

Question 86

CDK is only active when:

Answer 86

Specific cyclin is attached to it

Question 87

Active CDK

Answer 87

Regulates specific cell cycle phases