Bio 110

Question 1

How many different types of cells does E. coli have?

Answer 1

one type of cell

Question 2

How many different cell types does yeast have?

Answer 2

three types: haploid, diploid

Question 3

How many different cell types does Hydra have?

Answer 3

20-25

Question 4

How many different cell types does a California Black Oak have?

Answer 4

one

Question 5

How many different cell types do YOU have?

Answer 5

200

Question 6

What types of microscopes are there?

Answer 6

Light, fluorescence, electron

Question 7

what does a microscopy do

Answer 7

DECTECTS, MAGNIFIES, AND RESLOVES

Question 8

what is resolution?

Answer 8

The ability to distinguish between two closely positioned objects

Question 9

What is absorption?

Answer 9

When light passes through an object the intensity is reduced depending upon the color
absorbed

Question 10

What is refraction?

Answer 10

Direction change of a ray of light passing from one transparent medium to another with different
optical density

Question 11

What is diffraction?

Answer 11

Light rays bend around edges; this affects the image produced

Question 12

What is dispersion?

Answer 12

Separation of light into its constituent wavelengths when entering a transparent medium - the change of refractive index with wavelength

Question 13

Brightfield Microscopy

Answer 13

Modern microscopes magnify both in the objective
and the ocular and thus are called “compound
microscopes”
Ocular: Re-magnifies the specimen and
allows for visualization of the specimen

Prism (not shown): bends the light rays that
come from the objective into the ocular
Objective: magnifies the specimen
Condenser: focuses light through the specimen
Light source: illumination

Question 14

Fluorescence Microscopy

Answer 14

A fluorescence microscope uses fluorescence instead of, or in addition to, reflection and absorption to study properties of cells
Fluorescence Microscopy uses filters to spectrally
separate light according to wavelength

Question 15

Scanning Electron Microscopy (SEM)

Answer 15

Allows for visualization of biological structures
and surfaces
Resolution is limited to about 10 nm
Stained (metal coated) areas are dark because
the metal scatters the electrons away from the
detector

Question 16

Pros and Cons of Electron Microscopy

Answer 16

Pros:
* Magnification and resolution is vastly improved compared to light
microscopy
* Cons:
* Requires fixations and special preparation (cannot view live cells)
* Preparation can introduce artifacts

Question 17

Which of the following statements is true?

Answer 17

The fluorescence microscope could use fluorescence, as well as reflection and absorption, to visualize specimens.

Question 18

Which lens focuses light on the sample?

Answer 18

The condenser lens.

Question 19

What is the total magnification of a sample if you use a 100X objective combined with a 10X ocular lens in a compound microscope?

Answer 19

1000X

Question 20

What is the liquid bilayer made up of?

Answer 20

A hydrophilic head and a hydrophobic tail

Question 21

What is amphipathic?

Answer 21

To a molecule that
has hydrophilic and hydrophobic
portions

Question 22

Cell Membranes

Structure and Functio

Answer 22

Composed of phospholipids, proteins, and carbohydrates.

Functions include compartmentalization, selective permeability, communication, and structural integrity.

Question 23

Factors Affecting Membrane Fluidity

Answer 23

Lipid Composition: Cholesterol modulates fluidity; saturated vs. unsaturated fatty acids impact movement.

Lipid Structure: Cis-unsaturated fatty acids increase fluidity.

Temperature: Higher temperatures increase fluidity; lower temperatures decrease it.

Question 24

Experimental Techniques for Membrane Fluidity

Answer 24

FRAP (Fluorescence Recovery After Photobleaching): Measures lateral diffusion of membrane components.

Electron Spin Resonance (ESR): Assesses membrane lipid mobility

Question 25

Protein Structure and Membrane Embedding

Answer 25

Alpha helices and beta sheets provide stability within the membrane. Alpha helices span the membrane; beta barrels form pore-like structures

Question 26

Lipid-Linked Proteins

Answer 26

Attached via lipid anchors (GPI-anchored, prenylated, myristoylated proteins).

Question 27

Molecular Transport in Membranes

Answer 27

Carrier vs. Channel Proteins: Channels allow passive diffusion; carriers undergo conformational changes. Passive vs. Facilitated Diffusion: Passive (e.g., oxygen diffusion), Facilitated (e.g., glucose transport via GLUT). Active Transport Proteins: Examples include Na+/K+ pump, H+ ATPase, Ca2+ ATPase.

Question 28

Electrochemical Gradients

Answer 28

Formed by ion pumps (e.g., Na+/K+ ATPase). Drive secondary active transport and maintain membrane potential.

Question 29

Key Transport Terms

Answer 29

Uniport, Symport, Antiport: Types of transport mechanisms. Facilitated Diffusion, Osmosis: Passive transport processes. Membrane Potential, Solute, Solvent, Solution, Aqueous Solution: Key terms in transport.

Question 30

Experimental Techniques for Membrane Transport

Answer 30

Patch-Clamp: Measures ion channel activity. Radioactive Labeling: Tracks solute movement.

Question 31

Neuronal Signaling and Membranes

Answer 31

Electrical to Chemical to Electrical Conversion: Action potentials trigger neurotransmitter release, which binds to receptors to regenerate electrical signals. Channels Involved: Voltage-gated Na+/K+ channels, ligand-gated ion channels. Sodium-Potassium Pump: Uses ATP to maintain ion gradients.

Question 32

Ion Concentration Inside vs. Outside the Cell

Answer 32

Na+ (low inside, high outside) K+ (high inside, low outside) Ca2+ (very low inside, high outside) Cl- (low inside, high outside)

Question 33

Membrane Adaptations in High-Temperature Environments

Answer 33

Increased saturated lipid content. Enhanced cholesterol levels for stability. Specialized heat shock proteins to maintain function.

Question 34

Brightfield Microscopy

Answer 34

Magnification: Up to ~1000x Resolution: ~200 nm Contrast Mechanism: Uses staining techniques to enhance contrast. Experimental Use: Used for viewing fixed, stained specimens such as bacteria and tissue sections.

Question 35

Scanning Electron Microscopy (SEM)

Answer 35

Magnification: Up to ~500,000x Resolution: ~1-10 nm Contrast Mechanism: Electron beams scan the surface, secondary electrons provide contrast. Experimental Use: Used for detailed 3D surface imaging of cells and materials.

Question 36

Transmission Electron Microscopy (TEM)

Answer 36

Magnification: Up to ~2,000,000x Resolution: ~0.1 nm Contrast Mechanism: Electron beams pass through thin sections, staining with heavy metals enhances contrast.

Question 37

Which of the following is not a cell membrane function?

Answer 37

Transfer of genetic material

Question 38

The two layers of the lipid bilayer are identical.

Answer 38

False

Question 39

Which of the following statements is true about the eukaryotic cell membrane?

Answer 39

Saturated lipids make the membrane less fluid

Question 40

Phospholipids are synthesized in the Golgi apparatus.

Answer 40

False

Question 41

The microscopy method to determine whether a membrane is fluid is called:

Answer 41

Fluorescence Recovery After Photobleaching (FRAP)

Question 42

Alpha-helices and beta-sheets are common protein folding patterns.

Answer 42

True

Question 43

Membrane transport proteins are most likely which type of membrane protein?

Answer 43

Transmembrane

Question 44

Ion channels mostly likely contain which type of protein domains?

Answer 44

Beta barrel

Question 45

The alpha-helices of a multi-pass transmembrane protein are not amphipathic

Answer 45

False

Question 46

The surface localization of some membrane proteins is restricted to specific areas of the plasma membrane. Which of the following is NOT a mechanism for this restriction:

Answer 46

Proteins localized within lipid rafts

Question 47

Glycoproteins are glycosylated exclusively in the external region of the protein

Answer 47

True

Question 48

Which of the following is not a function of membrane proteins:

Answer 48

Permeability barrier

Question 49

The process of active transport

Answer 49

could be coupled to ATP hydrolysis.