Biology Exam Iii

Front 1

What cell component controls cell structure and movement?

Back 1

Cytoskeleton

Front 2

What two main components make up the cytoskeleton?

Back 2

Actin and Microtubules

Front 3

Three main types of cytoskeleton

Back 3

Microfilaments, Intermediate Filaments, and Microtubules

Front 4

Characteristics of Intermediate Filaments

Back 4

1. Mainly for structure support
2. Toughest and most durable
3. Span the cytosol
4. Link cells at cell junctions
5. Strengthen cell junctions

Front 5

What is a desmosome?

Back 5

Junctions made between cells

Front 6

Eight tetramers of intermediate polypeptides makes

Back 6

One rope of intermediate filament

Front 7

Characteristics of intermediate filament proteins

Back 7

1. Middle has the chemical capacity to make more of itself
2. The end globular proteins anchor to one another
3. Work as cell's rebar

Front 8

Intermediate Filament Chart

Back 8

Slide 7

Front 9

Intermediate filaments associate with

Back 9

Microtubules and Plectin (links IF to other proteins)

Front 10

How are IF 'unraveled' in the nuclear lamina?

Back 10

Phosphorylation

Front 11

Purpose of Microtubules

Back 11

Movement and organization center (centrosomes)

Front 12

Microtubules are made up of...

Back 12

Protein heterodimers of tubulin.

Front 13

Protofilament

Back 13

Long strand of tubulin heterodimer.

Front 14

Tubulin

Back 14

Abundant protein found in cells

Front 15

Gammatubulin grows out of

Back 15

Microtubules

Front 16

Which ends grow away from gammatubulin?

Back 16

Plus + Ends

Front 17

Why do we need gammatubulin?

Back 17

Allows organization of microtubules at right time/place.

Front 18

GTP binds to tubulin _______ the end of the microtubule

Back 18

Stabilizes

Front 19

GDP binds to tubulin _______ the end of the microtubule

Back 19

Depolymerizes

Front 20

Capping microtubule proteins does two things..

Back 20

1. Create polarity of the cell
2. Stimulates growth in a direction

Front 21

Two outcomes of creating polarity in the cell

Back 21

1. Microtubules help create axons
2. Direct movement and transport

Front 22

Two types of motor proteins used for movement in microtubules

Back 22

1. Dynein- toward minus end
2. Kinesin- toward plus end

Front 23

How could a microtubule allow flagella movement?

Back 23

Motors to help crosslink other microtubules

Front 24

How can microtubules bend?

Back 24

Fixed link proteins allow microtubules to bend

Front 25

What kind of filament is actin?

Back 25

Microfilament

Front 26

Actin's job in the cell

Back 26

Maintain shape and contraction

Front 27

Globular actin

Back 27

Single polypeptide of actin

Front 28

Filamentous actin

Back 28

Chain of actin

Front 29

Dynamic instability of F-actin is...

Back 29

It can add or subtract from either end with ATP.

Hydrolization favors subtraction

Front 30

Actin must ______ to function

Back 30

Couple and interact with other proteins

Front 31

Various functions of actin

Back 31

Slide 28

Front 32

_____ and ______ bind together to form cell cortex

Back 32

Actin and Spectrin

Front 33

Actin's role in cell mobility

Back 33

1. Rearrange cell so it can walk along the matrix
2. Repolymerizes filaments to favor movement

Front 34

Filopodium –
Lamellipodium –
Contractile Bundle –

Back 34

Filopodium – long feeler of actin
Lamellipodium – fills in space between filopodium
Contractile Bundle – linked the filopodium and Lamellipodium to the rest of the cell

Front 35

Describe the relationship between actin and myosin

Back 35

Myosin helps move the filaments of actin through contraction

Front 36

Main motor component of muscle contractions

Back 36

Myosin

Front 37

What area of myosin associates with actin?

Back 37

Myosin heads

Front 38

Muscle cells have multiple ____

Back 38

Nuclei

Front 39

Myofibril

Back 39

Composed of myosin II and actin bundled together = (sarcomere)

Front 40

Order from sarcomere to muscle

Back 40

Sarcomere --> Myofibril --> Muscle Cell --> Muscle Itself

Front 41

Sarcomere

Back 41

Contractile unit of myosin II and actin

Also makes up myofibril

Front 42

Z-Disc

Back 42

Unit actin is bound to

Refer to Slide 38

Front 43

What happens to the sarcomeres during contraction?

Back 43

The myosin/actin interaction pulls heads inward and ATP hydrolysis drives contraction.

Front 44

Examples for:

Microfilaments
Intermediate Filaments
Microtubules

Back 44

Microfilaments - actin
Intermediate filaments - various
Microtubules - alpha and beta tubulin

Front 45

Protofilament

Back 45

Long strand of tubulin heterodimers

Front 46

Microtubules have polarity - which ends point away from gammatubulin?

Back 46

Plus end