Exam2 Flashcards
Fluid Mosaic Membrane Assumption
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
Small
Polar: Polar Molecules
Facilitated Diffusion
Na+/K+
.
Non-Polar Molecules
Simple Diffusion
Facilitated Diffusion
CO2, O2,
Medium
Steroids, Carotenoids, fats
Simple Diffusion
Facilitated Diffusion
Glucose, Amino Acids
Facilitated Diffusion
Large
1000 Daltons proteins
Lipids
Endo/exocytosis
DNA/RNA
Endo/Exocytosis
Ion Channels
Uniport → One way
● Symport→One way, but with two solutes
● Antiport→ Two direction, with two solutes
Osmosis
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
Facilitated Transport
Uses Integral Membrane
Proteins
• Small & Charged (polar)
Molecules
• Passive Transport
• (High→ Low)
• No energy required since
going DOWN the
concentration gradient
Active Transport
Needs energy (ATP)
• Low→ High
Concentrations
• AGAINST
concentration gradient
• Phosphorylating
alters conformity
• Dephosphorylation
alters conformity
Types of Cell Communication
- Direct Contact
a. cell surface signal and receptors - Autocrine and Paracrine Signaling
a. signal molecules (neurotransmitters) - Endocrine
a. Hormones (adrenaline) - Synaptic
a. Neural signaling
Signaling Molecules found
in Cell Communication
Hormones, Ions, Proteins
(Biochemical or physical
signals)
• ie. Epinephrine,
hormones,
neurotransmitters
After first messenger; secondary messengers
Signal receptors are converted to Secondary Messengers
• Starts a signaling phosphorylation cascade (chain reaction)
• Responds with physiological response
• Gene Expression, metabolic activity, defense, etc.
1st Messengers
First messenger binds to receptors on the membrane
G Protein-Linked Receptors RECOGNIZES 1st Messenger
. 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
Bacterial Chemical Response
Produces proteins that leads to lysis and
death in the host cell
○ Shigella, tetanus, vibrio cholerae, anthrax,
and salmonella
■ Affects cellular processes
Key thing to know: Restriction methylation system
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
Protists
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
Fungal Cell wall
Made up of modified polysaccharide chitin
○ contains chemicals that are antibiotic or toxic
● Grows rapidly and can create cellulase or
keratinase (enzymes)
Humans and Animal Physical Barriers
Skin, fur, mucous coatings, and exo-skeleton
● Physiological fight-or-flight response
● Extreme pH in our stomachs (pH: 1.5 - 3.5)
● Tight junctions
Plants have a wide variety of physical barriers
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
Plants can regrow leaves, stems, etc.
Useful for fighting infections or repairing
damaged tissues
Innate Immunity
Involves macrophages
that are non-specific
○ releases cytokines
and chemokines
● Mast cells secrete
histamines
○ dilate blood vessels
Adaptive Immunity
Highly specialized
● Constant throughout
your body…
2 types of Adaptive
Immunity
1. Humoral Immunity
2. Cellular Immunity
Humoral Immunity
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
Cell Mediated Immunity
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
