Exam 1 – Lecture 4: Non-membranous Organelles

Question 1

What is the structure of microtubules?

Answer 1

Non-branching and rigid

Hollow tubes of protein polymers

Question 2

What do microtubules do?

Answer 2

Form microtubular organizing centers (MTOC)

Question 3

What do MTOCs do?

Answer 3

Form the basis of spindles

Question 4

What do microtubules have a role in?

Answer 4

Intracellular transport / motion, cell shape, mitosis

Question 5

What are 2 types of microtubules?

Answer 5

α and β tublin

Question 6

What moves along micotubules?

Answer 6

Dyneins and kinesins

Question 7

What do dyneins do?

Answer 7

Carry things to the cell

Question 8

What do kinesins do?

Answer 8

Carry things away from the cell

Question 9

Where is actin found?

Answer 9

In all cells

Question 10

What is the structure of actin?

Answer 10

Helical array

Question 11

What are the 2 types of actin?

Answer 11

Globular (G) and filamentous (F) actin

Question 12

What do the actin associated proteins do?

Answer 12

Binding
Severing
Capping
Cross-linking
Motor

Question 13

What are the contractile proteins in muscle?

Answer 13

Actin and myosin

Question 14

What is the funtion of actin?

Answer 14

Anchor, motion, μvilli

Question 15

What does anchor mean?

Answer 15

Attach cells to things around it

Question 16

What are intermediate filaments like?

Answer 16

Highly variable, non-polar polymers

Cable-like structure

Question 17

What do intermediate filaments do?

Answer 17

Cell-cell and cell-matrix interaction

Question 18

What are examples of intermediate filaments

Answer 18

Keratins
Vimentin and vimentin-like proteins
Neurofilaments
Laminin

Question 19

What does non-polar mean?

Answer 19

Non-directional

Question 20

How does the lowest level of epithelium attach to the basement membrane?

Answer 20

Intermediate filaments

Question 21

What are intermediate filaments very important in?

Answer 21

Cancer diagnostics

Question 22

What is keratin prominent in?

Answer 22

Epithelial tissues

Question 23

What is vimentin prominent in?

Answer 23

Connective tissues

Question 24

What is the focal point for MTOC?

Answer 24

Centrioles

Question 25

What are centrioles?

Answer 25

Cylindrical triplets of microtubules Mitotic spindles Basal bodies

Question 26

What are basal bodies?

Answer 26

The attachment centrioles for cilia and flagella

Question 27

What are inclusions?

Answer 27

Cytoplasmic accumulations

Question 28

What are examples of cytoplasmic accumulations?

Answer 28

``` Lipofuscin Hemosiderin Glycogen Lipid droplets Crystalline ```

Question 29

What is the yellow of a bruise?

Answer 29

Lipofuscin

Question 30

What is glycogen?

Answer 30

Where glucose is stored

Question 31

Why is glycogen not seen on H and E?

Answer 31

It is water soluble

Question 32

What cannot be seen on H and E? What do they become?

Answer 32

Lipids | Clear spots

Question 33

What are ribosomes the site of?

Answer 33

Protein translation

Question 34

What are the 2 types of ribosomes?

Answer 34

40s and 60s

Question 35

What are ribosomes the target of?

Answer 35

Many antibiotics

Question 36

What are ribosomes made of?

Answer 36

RNA and protein

Question 37

What is the nucleus envelope like?

Answer 37

Membrane bound

Question 38

What is stored in the nucleus of eukaryotes?

Answer 38

Genetic information | Chromatin

Question 39

What is chromatin?

Answer 39

DNA and protein

Question 40

What is the substance in a nucleus?

Answer 40

Nucleoplasm

Question 41

What is euchromatin?

Answer 41

Active, light in microscope Not electron dense Spread out and read DNA

Question 42

What is heterochromatin?

Answer 42

Inactive, dark on microsope Electron dense Chromosomes are not very active

Question 43

What are chromosomes like in the nucleus?

Answer 43

Discrete | Most times not visible (mitosis)

Question 44

What is the nucleolus?

Answer 44

Site of RNA synthesis Initial ribosomal assembly Cell cycle control