Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Histo Quiz 1 > Cell Structure 1 > Flashcards

Cell Structure 1 Flashcards

1
Q

What are the 4 types of tissues in the body?

A
  1. Nervous
  2. Epithelial
  3. Connective
  4. Muscle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the germ layers from which all tissues develop?

A
  1. Ectoderm
  2. Endoderm
  3. Mesoderm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What types of tissues does the ectoderm give rise to?

A

Nervous and epithelial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What types of tissues does the endoderm give rise to?

A

Epithelial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What types of tissues does the mesoderm give rise to?

A

Epithelial, connective, and muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does amphipathic mean?

A

Has both polar (hydrophilic) and nonpolar (hydrophobic) regions attached to it.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the purpose of the cell membrane’s fluidity?

A

To allow lateral diffusion of lipid molecules and membrane proteins.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe membrane permeability.

A

Impermeable to charged ions.

Permeable to small nonpolar and small polar molecules.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are some functions membrane proteins perform?

A

Transport, signaling, adhesion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Name the two parts of the phospholipid head and their charges.

A

Amino alcohol: positive

Phosphate: negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Name the backbone of the phospholipid.

A

Glycerol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are phospholipids named after?

A

The amino-alcohol that forms the head group.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

A kink in the unsaturated fatty acid chain helps with…

A

maintaining membrane fluidity, preventing phospholipids from packing too closely together.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the components of phospholipids?

A

Two fatty acid tails (one unsaturated); glycerol backbone; phosphate bridge (head); amino alcohol (head).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the components of cholesterol?

A

One fatty acid tail; a rigid, planar, steroid ring structure; a polar head group (hydroxyl)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Where does cholesterol go?

A

Intercollates b/w phospholipids.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What does cholesterol do?

A
  • reduces permeability to small molecules
  • stiffens membrane for mechanical strength
  • at high concentrations, prevents further packing of phospholipid
  • contributes to formation of lipid rafts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

With an increase in cholesterol, fluidity…

A

decreases, then plateaus after a certain point. (Adding in cholesterol reduces fluidity as low as it can go.)

19
Q

Lipid rafts are…

A

concentrations of specific proteins crucial for cell-cell recognition on lipid membrane

20
Q

Name the components of glycolipids.

A

2 fatty acid chains, polar head, carbohydrates attached to head group.

21
Q

What do glycolipids do?

A

Contribute to the glycocalyx.

22
Q

Where are glycolipids present?

A

Only in outer leaflet of lipid bilayer. Form a sugar coating around membrane of most cells.

23
Q

What happens in Tay-Sachs disease?

A

Defect in metabolism of gangliosides (complex lipids) in neurons. Inability to turn over gangliosides results in buildup to toxic levels, causing neurons to die. Defect in enzyme that metabolizes gangliosides.

24
Q

What are the two forms of membrane proteins?

A

Integral: embedded in or traverse membrane
Peripheral: associated with integral proteins but not directly embedded in membrane; adherent to cytoplasmic or extracellular surface of membrane.

25
Q

What are the functions of membrane proteins?

A
  1. Transport of ions and molecules
  2. Cell-cell recognition and adhesion
  3. Signal transduction
26
Q

What is the purpose of freeze fracturing?

A

Allows us to visualize which side of the lipid bilayer proteins adhere primarily to.

27
Q

What are the two resultant sides of freeze fracturing, and which do most proteins cling to?

A

P-face (protoplasmic): most integral membrane proteins stick with this side because they are anchored to the cytoplasmic side of the bilayer/interacting w/ some part of the cytoskeleton.

E-face (extracellular)

28
Q

What are the two sources of carbohydrates in the glycocalyx?

A

Glycolipids and proteins (either integral or secreted by other cells and absorbed to membrane)

29
Q

What are the functions of the glycocalyx?

A
  1. Prevent infection: it is strongly negatively charged (polyanionic) on the outer surface to repulse bacteria that have been coated in negatively-charged antibodies.
  2. Protects cell from chemical or mechanical damage by acting as a barrier above the delicate lipid membrane.
  3. Important for cell-cell recognition: carbohydrate composition helps identify what kind of cell it is so it can interact or not interact w/ other cells.
30
Q

Movement of ions and small molecules across membrane is controlled by:

A 
Transport proteins (e.g. ion channels)
Carrier proteins
31
Q

Movement of macromolecules and particulate matter across membranes is controlled by:

A

Endocytosis (outside to inside)

Exocytosis (inside to outside)

32
Q

What are the 3 types of endocytosis?

A

Pinocytosis (cell drinking)
Receptor-mediated endocytosis
Phagocytosis

33
Q

What is pinocytosis?

A

Bulk uptake of fluids from extracellular medium into interior of cell and sent to destinations w/in cells by vesicles.

34
Q

What is receptor-mediated endocytosis?

A

Capturing of specific molecules that the cell needs by having receptors on the cell surface that bind to those molecules and capture them, then bring them into the cell through the cytoplasmic vesicle.

35
Q

What is phagocytosis?

A

Only performed by special phagocytic cells that have target receptors for bacteria or cell debris. Taking up of large particles via pseudopodia that engulfs the particle and brings it in via a large phagocytic vesicle to fuse with lysosomes.

NOT clathrin-driven; pseudopodia driven by changes in actin cytoskeleton.

36
Q

What drives invagination during pinocytosis?

A

Clathrin coating on cytoplasmic side of cell membrane.

37
Q

What drives pinching off of endocytic vesicles in pinocytosis?

A

Dynamin: a GTPase that forms a collar to form the missing side of the vesicle.

38
Q

What are the purposes of pinocytosis?

A

To bring nutrients into the cell and to help maintain membrane’s surface area, shape, and size by taking out old, worn parts of membrane.

39
Q

How does receptor-mediated endocytosis work for cholesterol?

A

The cell produces LDL receptors and implants them on the extracellular surface to bind LDL. When LDL binds to receptors inside a clathrin-coated pit, the clathrin causes invagination of the membrane into a coated vesicle. The clathrin dissociates, and the vesicle becomes a CURL (component for uncoupling of receptor and ligand - acidic) to dissociate the LDL from the receptors. The receptors return to the cell surface with the membrane, while the LDL in the endosome proceeds to fuse w/ a lysosome that can break down the LDL and release cholesterol.

40
Q

What is phagocytosis limited to?

A

MACROPHAGES AND NEUTROPHILS

41
Q

What is a phagosome?

A

the large vesicle containing engulfed material in phagocytosis

42
Q

What is the purpose of exocytosis?

A

Export of material out of the cell (synthesized materials made in the cell) packaged in vesicles

43
Q

What materials travel in exocytosis and where?

A

Things that are going to be secreted from the cell are inside the vesicles; integral membrane proteins are located on the vesicle membrane itself and will then merge with the cell membrane upon release of vesicle contents.

44
Q

What catalyzes the fusion of exocytic vesicles with the cell membrane?

A

Fusogenic proteins (differ from cell to cell)

Histo Quiz 1 (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions