Histo: Plasma Membrane, Cytoskeleton, Nucleus, Connective Tissue

Question 1

List 4 main components of the plasma membrane

Answer 1

phospholipids, proteins, carbohydrates (glycocalyx), cholesterol

Question 2

The phospholipid bilayer of the plasma membrane has an inner layer called the __ ___ and an outer
layer called ____ _____.

Answer 2

P-face, E-face

Question 3

Define Amphipathic

Answer 3

molecule with 2 parts: hydrophilic and hydrophobic regions

Question 4

T/F Membrane fluidity is dependent on cholesterol and temperature

Answer 4

True

Question 5

List the 6 integral protein categories:

Answer 5

pumps, channels, receptors, linkers, enzymes, structural proteins

Question 6

Describe Receptor mediated endocytosis in your own words. You must describe how clathrin, adaptor and dynamin proteins work together

Answer 6

Process where ligands bind with surface receptors. Clathrin and adaptor proteins attach to binding sites for ligands. Then dynamin proteins cause constricting loops (invagination) of the bound ligands to form coated vesicles.

Question 7

What is the function of a ribosome?

Answer 7

to transcribe mRNA; catalyze the formation of peptide bonds, participates in protein synthesis

Question 8

What is the function of the rough endoplasmic reticulum (Rough ER)?

Answer 8

a membrane bound organelle that ribosomes bind to, during polypeptide synth, participates in protein syth and protein modification

Question 9

What is the function of the smooth endoplasmic reticulum (Smooth ER)?

Answer 9

a membrane bound organelle, participates in protein syth and protein modification. Can store Ca, glycogen and do steroid hormone synth.

Question 10

What is the function of the mitochondrion?

Answer 10

a membrane bound organelle that participates in ATP syth and aerobic respiration

Question 11

What is the function of the the golgi apparatus?

Answer 11

a membrane bound organelle that participates in protein synth and modification. It gives rise vesicles (secretory, lysosomes)

Question 12

What is the function of the lysosome?

Answer 12

a membrane bound organelle filled with degradative enzymes

Question 13

What protein are microtubules made out of?

Answer 13

globular protein subunits: a-tubulin and b-tubulin

Question 14

What is the structure of microtubules?

Answer 14

hollow tube structure - made of dimers (a+b tubulin) 13 dimers in 1 circle

Question 15

What is the main function of microtubules?

Answer 15

To maintain cell shape.

Question 16

What structures can microtubules form?

Answer 16

cilium and flagellum

Question 17

What proteins are microfilaments made of?

Answer 17

Actin filaments (protein)

Question 18

What is the overall structure of a microfilament? What are the units and subunits called?

Answer 18

a rope like structure; helical, combines two strands. strands are composed individual G-actin ‘beads’; when polymerized in strand known as F-actin

Question 19

What is the main function of microfilament?

Answer 19

they are the cores of microvilli, also play role in cytokinesis

Question 20

What specific cellular structures do microfilaments support/ form?

Answer 20

Microvilli

Question 21

What are the 6 types of intermediate filaments?

Answer 21

Cytokeratin: epithelial origin
Vimentin: mesodermal origin
Desmin: muscle cell origin
Neuro-filament protein: nerve cell origin
Glial fibrillary acidic protein (GFAP): glial cell origin
Lamin: inner side of nuclear membrane

Question 22

What are inclusion bodies? What types? What are their structural features?

Answer 22

they are accumulated metabolites or other substances ie viral particles, protein aggregates etc.

Types: glycogen, lipid droplets, lipofuscin, melanin

structure: non membrane bound, shape and size vary

Question 23

What is the structure of cholesterol?

Answer 23

amphipathic: polar hydrophilic head and nonpolar hydrophobic tail

Question 24

What are the two types of Integral Proteins?

Answer 24

transmembrane and multipass

Question 25

What do peripheral proteins do?

Answer 25

bind to phospholipids or integral proteins

Question 26

What is an example of a peripheral protein?

Answer 26

Spectrin

Question 27

What is spectrin?

Answer 27

peripheral protein that stabilizes the cell membrane of RBC's

Question 28

What are the three ways to transport through plasma membrane?

Answer 28

Passive, active and vesicular transport

Question 29

What is passive transport?

Answer 29

simple diffusion (via channel, pump); no energy required. move down electrochem gradient

Question 30

What are the types of active transport?

Answer 30

primary and secondary: energy required, goes against electrochem gradient via carrier protein

Question 31

What is vesicular transport?

Answer 31

endocytosis and exocytosis

Question 32

What are the types of endocytosis?

Answer 32

phagocytosis, pinocytocis, receptor mediated endocytosis

Question 33

What is phagocytocis?

Answer 33

engulfiing endocytosis: creates phagosome/vacuole

Question 34

What is pinocytosis?

Answer 34

drinking endocytosis; forms a pinocytotic vesicle containing liquid

Question 35

What is exocytosis?

Answer 35

movement of large molecules from inside to outside cell via vesicular transport

Question 36

What does a cell use to execute exocytosis?

Answer 36

uses secretory vesicles/ secretory granules

Question 37

What are the 5 types of signal reception?

Answer 37

1) endocrine 2) paracrine 3) synaptic 4) autocrine 5) juxtacrine

Question 38

What is endocrine signaling?

Answer 38

hormones are carried in blood to target cells in body

Question 39

what is paracrine signaling?

Answer 39

chemical ligand diffuses in extracellular fluid. rapid metabolism, effect is local

Question 40

What is synaptic signaling?

Answer 40

neurotransmitters act on adjacent cells via synapses

Question 41

What is autocrine signaling?

Answer 41

signals bind receptors on the same cell

Question 42

what is juxtacrine signalling?

Answer 42

cell membrane bound proteins signal when making direct physical contact

Question 43

What is the shape of a nucleus?

Answer 43

Size and shape vary: spherical, ovoid, elongated, disk, lobulated etc

Question 44

How many nuclei per cell?

Answer 44

usually 1 multiple: heptocytes none: erythrocytes

Question 45

Two main types of nucleus?

Answer 45

Leptochromatic and Pachychromatic

Question 46

What are leptochromatic nuclei?

Answer 46

Nuclei w/ more open/ available DNA (euchromatin) which is lighter colored cytoplasm has a lot of rER and Golgi

Question 47

What are pachychromatic nuclei?

Answer 47

Nuclei w/ more tightly packed DNA (heterochromatin) which is darker colored cytoplasm has few organelles

Question 48

What is the nucleus made of and describe each function

Answer 48

Nuclear envelope: two layers of nuclear membrane nucleolus: synth of rRNA Chromatin: - euchromatin (lighter), - heterochromatin (darker)

Question 49

What is the nuclear envelope

Answer 49

Enclosing the nuclear material, and separating it from the cytoplasm Outer nuclear membrane: It is continuous with the membrane of rER Inner nuclear membrane

Question 50

What is the space between two nuclear membranes called and its features

Answer 50

pernicular space: continuation w/ space inside the rER

Question 51

What are nuclear pores?

Answer 51

openings in the nuclear envelope that permit passage of molecules bidirectionally

Question 52

What is the nucleolus

Answer 52

Dense structure inside the nucleus Well developed (prominent) in cells with very active protein synthesis Nucleolus contains: - DNA (part of chromosomes): genes that encode for the rRNA formation - rRNA & protein

Question 53

What is the function of the nucleolus?

Answer 53

site for the synthesis of the rRNA

Question 54

What is chromatin?

Answer 54

Consists of double stranded DNA associated with nucleoprotein called HISTONES Euchromatin: - Transcriptionally active - Lightly stained region - Open/ available DNA Heterochromatin: - Transcriptionally inactive - Location: peripheral, around nucleolus or scattered in nucleoplasm. - Deeply stained region - Tightly packed DNA