Exam2

Question 1

Fluid Mosaic Membrane Assumption

Answer 1

Membranes aren’t rigid; they are fluid
2. London Dispersion force are the key forces
that binds the membrane together
3. Fluidity and Saturation are dependent on
temperature
4. Membranes are two-side structure

Question 2

Small

Answer 2

Polar: Polar Molecules
Facilitated Diffusion
Na+/K+
.
Non-Polar Molecules
Simple Diffusion
Facilitated Diffusion
CO2, O2,

Question 3

Medium

Answer 3

Steroids, Carotenoids, fats
Simple Diffusion
Facilitated Diffusion

Glucose, Amino Acids
Facilitated Diffusion

Question 4

Large

Answer 4

1000 Daltons proteins
Lipids
Endo/exocytosis

DNA/RNA
Endo/Exocytosis

Question 5

Ion Channels

Answer 5

Uniport → One way
● Symport→One way, but with two solutes
● Antiport→ Two direction, with two solutes

Question 6

Osmosis

Answer 6

Diffusion of water from High to Low
concentrations
• Hypo→ greater solute
concentrations; bag swells
• Iso→ equal solute concentrations;
bag stays the same
• Hyper→ Less solute
concentrations; bag shrivel

Question 7

Facilitated Transport

Answer 7

Uses Integral Membrane
Proteins
• Small & Charged (polar)
Molecules
• Passive Transport
• (High→ Low)
• No energy required since
going DOWN the
concentration gradient

Question 8

Active Transport

Answer 8

Needs energy (ATP)
• Low→ High
Concentrations
• AGAINST
concentration gradient
• Phosphorylating
alters conformity
• Dephosphorylation
alters conformity

Question 9

Types of Cell Communication

Answer 9

1. Direct Contact
   a. cell surface signal and receptors
2. Autocrine and Paracrine Signaling
   a. signal molecules (neurotransmitters)
3. Endocrine
   a. Hormones (adrenaline)
4. Synaptic
   a. Neural signaling

Question 10

Signaling Molecules found
in Cell Communication

Answer 10

Hormones, Ions, Proteins
(Biochemical or physical
signals)
• ie. Epinephrine,
hormones,
neurotransmitters

Question 11

After first messenger; secondary messengers

Answer 11

Signal receptors are converted to Secondary Messengers
• Starts a signaling phosphorylation cascade (chain reaction)
• Responds with physiological response
• Gene Expression, metabolic activity, defense, etc.

Question 12

1st Messengers

Answer 12

First messenger binds to receptors on the membrane
G Protein-Linked Receptors RECOGNIZES 1st Messenger

Answer 13

. Bacteria includes cell walls modified with NAM-NAG and a slimy layer
○ Filled with polysaccharides
■ blocks entry of viruses and antibiotics.
● Bacterias may also have pili or fimbriae
● Helps in adhering to surfaces

Question 14

Bacterial Chemical Response

Answer 14

Produces proteins that leads to lysis and
death in the host cell
○ Shigella, tetanus, vibrio cholerae, anthrax,
and salmonella
■ Affects cellular processes

Question 15

Key thing to know: Restriction methylation system

Answer 15

Defense mechanism found in bacteria/prokaryotes
● Methylase adds methyl groups to specific DNA sequences
○ Identifies own sequence of DNA as its own
■ Prevents foreign DNA from entering

Question 16

Protists

Answer 16

Some protists do not have a cell wall
○ they are protected by plasma membrane
■ Protists, paramecium, euglena, amoeba
● Some unicellular protists have cell wall structures!
○ cellulose, cell wall proteins, silica, and calcium carbonate
■ algae and diatoms

Question 17

Fungal Cell wall

Answer 17

Made up of modified polysaccharide chitin
○ contains chemicals that are antibiotic or toxic
● Grows rapidly and can create cellulase or
keratinase (enzymes)

Question 18

Humans and Animal Physical Barriers

Answer 18

Skin, fur, mucous coatings, and exo-skeleton
● Physiological fight-or-flight response
● Extreme pH in our stomachs (pH: 1.5 - 3.5)
● Tight junctions

Question 19

Plants have a wide variety of physical barriers

Answer 19

secondary cell wall, waxy coating, toxic exudates, etc.
○ these structures are made up of cellulose, hemicellulose, pectin, tanin,
and lignin
Plants also produces secondary metabolites!
● Curmurin , Capsaicin, and Azadirachtin
○ anti-bacterial or anti-inflammatory response

Question 20

Plants can regrow leaves, stems, etc.

Answer 20

Useful for fighting infections or repairing
damaged tissues

Question 21

Innate Immunity

Answer 21

Involves macrophages
that are non-specific
○ releases cytokines
and chemokines
● Mast cells secrete
histamines
○ dilate blood vessels

Question 22

Adaptive Immunity

Answer 22

Highly specialized
● Constant throughout
your body…
2 types of Adaptive
Immunity
1. Humoral Immunity
2. Cellular Immunity

Question 23

Humoral Immunity

Answer 23

Antigens bind to specific proteins on a
virus or bacteria.
○ Antigen is recognized by B-cell
(mediated by helper T-Cells)
B-cells replicates into plasma B-cells and
memory B-cells.
● Plasma B-Cells produces antibodies
to fight against an infection.
○ antibodies neutralize toxic
proteins by pathogens
○ Marks pathogen for degradation
by Killer T-cells
● Memory B-cells produces an
ever-lasting protection after the initial
protection

Question 24

Cell Mediated Immunity

Answer 24

Cytotoxic T-cell
○ recognizes a host cell
that has been infected by
a pathogen and lysis it
■ prevents host cell
from producing
pathogens
■ Triggered by vaccines
for a particular
proteins