Ch 3

Question 1

What are the fundamentals of modern cell theory?

Answer 1

1. All living things are composed of cells/cell products
2. All cells come from other cells
3. The cell is the most fundamental, functional unit of life
4. An organism’s function/structure are due to the function/structure of its cells
5. Calls from different species show metabolic and chemical similarities

Question 2

Name the nine cell shapes

Answer 2

Squamous
Cuboidal
Columnar
Stellate
Polygonal
Fibrous
Spheroid/ovoid
Discoid
Fusiform

Question 3

What is the most fundamental cell organelle?

Answer 3

The cell membrane

Question 4

What are the components of the cytoplasm?

Answer 4

Cytosol
Cytoskeleton
Organelles
Inclusions

Question 5

What is a unit membrane, and which organelle are membrane-enclosed and which are not?

Answer 5

Unit membrane = a membrane formed from a phospholipid bilayer

Membrane-enclosed: nucleus, ER, lysosomes, peroxisomes, mitochondria, Golgi apparatus, plasma membrane

Not membrane-enclosed: centrosomes, ribosomes, basal bodies, centrioles

Question 6

Name the types of membrane lipids and their functions

Answer 6

1. Phospholipids: primary building block of the cell membrane, keep the membrane fluid
2. Cholesterol: stiffens the membrane
3. Glycolipids: used for cell ID (?). Form glycocalyx on exterior of cell

Question 7

Describe the two types of membrane proteins

Answer 7

Transmembrane: hydrophilic and hydrophobic portions. Can drift laterally in membrane, though some are attached to the cytoskeleton. Pass through the membrane. Most are glycoproteins.

Peripheral: only associated with one side one side of the membrane. Usually attached to the cytoskeleton.

Question 8

What are microvilli, and where would they likely be found?

Answer 8

Microvilli are short projections of the cell membrane supported by an actin core that can contract to bring things stuck to the microvilli into the cell. They aid in absorption and are found in the GI tract.

Question 9

What are cilia, and where are they found?

Answer 9

Cilia are cellular projections made of microtubules and dynein proteins. Motile cilia are found in the respiratory tract, brain ventricles, uterine times, and ductules of the testicles.

Question 10

Describe the structure of a cilium?

Answer 10

Axoneme made of 11 parallel sets of microtubules. 9 of the 11 sets form the anchoring basal body inside the cell. Dynein proteins walking along microtubules causes the cilium to wave.

Question 11

Talk about cystic fibrosis

Answer 11

Genetic mutation causes chloride pump to not be inserted in cell membrane. Usually chloride pumps generate a hypertonic ECF on the apical side of the cell. This leads to water flowing out of the cell, creating a saline later that coats the cilia of some epithelial cells. Mucus sits on top of this saline layer. The beating of the cilia moves the mucus out of the body (in the lungs = the mucocilia elevator). Lack of saline layer leads to mucus plugs in respiratory tract, pancreas.

Question 12

Compare and contrast cilium and flagellum

Answer 12

Same axoneme. Flagella are longer. No power/recovery stroke pattern for flagella.

Question 13

What’s the difference between active and passive transport? Give examples of each.

Answer 13

Active transport uses ATP (vesicular transport, sodium potassium pump), passive transport does not (filtration, diffusion, osmosis)

Note: carrier-mediated transport can be either

Question 14

Explain filtration and give an example

Answer 14

When particles are driven through a selectively permeable membrane due to pressure exerted by water. Example of passive transport. Nutrients filter through capillary walls.

Question 15

What’s the osmolality of plasma, normal saline?

Answer 15

Plasma: 300 mOs/L
Saline: 308 mOs/L

Question 16

What are the two types of carrier-mediated transport?

Answer 16

Facilitated diffusion

Active transport

Question 17

Explain specificity and relate it to the idea of a transport maximum (Tm)

Answer 17

Specificity refers to the fact that mediating transport proteins only bind to one type of ligand, which they then transport across the cell membrane. Because they only have so many binding sites, they reach a maximum rate of transport at a certain ligand concentration. Above this concentration, the rate of transport does not increase.

Question 18

List the three types of transport proteins

Answer 18

Uniport
Symport (cotransport)
Antiport (countertransport)

Question 19

Give the ATP:Na+:K+ ratio for the sodium potassium pump

Answer 19

1 ATP: 3Na+ out: 2K+ in

Question 20

Define secondary active transport and give an example

Answer 20

Secondary active transport is a process that does not require ATP, itself, but the conditions for which were established using ATP. Sodium-glucose transport protein

Question 21

What part of vesicular transport requires Ca2+?

Answer 21

Docking of the vesicle to the linking proteins during exocytosis

Question 22

What is the structure and function of the cytoskeleton?

Answer 22

Cytoskeleton provides cell structure and support. Necessary for movement and cell division. Allows for vesicular transport through cell. Made up of microtubules, intermediate fibers, and microfilaments.

Question 23

Explain the relationships between microtubules, protofilaments, and tubulin

Answer 23

Tubulin is the building block of protofilaments, which assemble into microfilaments

Question 24

Draw a nucleus, labels its parts. How many nuclei can a cell have?

Answer 24

Cells can have 0, 1, or many nuclei.
Parts: nuclear envelope, nuclear pores, chromatin, nucleolus (nucleoplasm is chromatin and nucleoli), nuclear lamina supporting nuclearenvelooe

Question 25

Discuss the structure and function of the smooth and rough ER

Answer 25

Smooth ER does not have bound ribosomes. Cisternae are more like branched tubes. Manufactures membranes. Synthesizes lipids and steroids. Stores Ca2+. Important for detoxification (including of alcohol).

Rough ER has flatter cisternae. Has bound ribosomes. Synthesizes proteins for export. Synthesizes phospholipids.

Question 26

Discuss ribosome structure and function

Answer 26

Non membrane-bound organelles. Made from RNA and protein. Translate mRNA into amino acid sequences.

Question 27

Discuss ribosome structure and function

Answer 27

Non membrane-bound organelles. Made from RNA and protein. Translate mRNA into amino acid sequences.

Question 28

Discuss the Golgi apparatus’ form and function

Answer 28

The Golgi synthesizes carbohydrates, modifies, packs and ships proteins. Vesicles containing Golgi products move from cisterna to cisterna from each cisterna’s cis side to its trans side.

Question 29

Discuss the structure and function of lysosomes

Answer 29

Lysosomes are membrane-enclosed organelles (singly enclosed in contrast to mitochondria and the nucleus). They digest substances through hydrolysis. Role in autophagy and autolysis.

Question 30

Discuss the structure and function of peroxisomes

Answer 30

Membrane-enclosed organelles that do not originated in the Golgi. Break down substances using oxidation reactions involving molecular oxygen. Form peroxide as a byproduct. Catalase breaks down hydrogen peroxide

Question 31

Discuss the structure and function of mitochondria

Answer 31

Double membrane-enclosed. Inner membrane has cristae. Inner most compartment is the matrix. Contains mtDNA. Inner membrane space. Synthesizes ATP.

Question 32

Discus the structure and function of the centriole. How does it relate to the centrosome?

Answer 32

Centriole is a short collection of microtubules. Two lie perpendicular in an area of cytoplasm called centrosome. Enable cell division

Question 33

What are cellular inclusions?

Answer 33

Non membrane-enclosed objects in cell. Two types: foreign bodies (e.g. phagocytosed bacteria), cell products (e.g. glycogen). Not essential for cell survival.