* Flashcards
(133 cards)
1
Q
amphoteric molecules
A
act as acids or bases depending on environment
2
Q
fat/ triacylglycerol
A
- glycerol + 3 fatty acid chains (hydrocarbon chain with carboxyl at end)
- ester linkage (COC)
3
Q
fatty acids length
A
14-20 carbons
4
Q
saturated (tristearate) / unsaturated (linseed oil)
A
- Saturated with hydrogens; no C=C double bonds; pack tightly; solid at room temp
- unsaturated: C=C double bonds; kinks, liquid at room temp (mono and polyunsaturated)
5
Q
sickle cell anemia
A
glutamic acid changed to valine
6
Q
2 types of secondary structures
A
- alpha helix
- beta pleated sheets
- goal is to maximize hydrogen bonding
7
Q
alzheimers causes
A
- amyloid plaques (a-peptide aggregates)
- misfolded Tau proteins (neurofibrillary tangles)
8
Q
cell bio approach
A
reductionist (as opposed to functionalist)
9
Q
invented the first compound microscope
A
zacharias janssen
10
Q
robert hooke
A
- coined term “cell”
- used light microscope to look at cork (plant tissue)
11
Q
leeuwenhoek
A
first to see living organisms
12
Q
cell theory
A
1) all organisms are composed of one or more cells (schleiden-plants; schwann-animals)
2) all cells arise from pre-existing cells (virchow)
3) the cell is the structural and functional unit of all living things
4) cells contain genetic information (DNA) they pass on to the next cell generation)
13
Q
basic propeties of cells
A
1) are alive (cultured cells)
2) highly complex and organized
3) have a genetic program
4) can produce more of themselves
(mitosis + meiosis)
5) acquire and utilize energy
6) carry out chemical reactions
7) engage in mechanical activities
8) respond to stimuli
9) capable of self-regulation (feedback circuits)
10) evolve (LUCA)
14
Q
prokaryotes
A
- unicellular
- small genome
- binary fission (asexual, one copy of chromosome)
15
Q
flagella
A
both prokar and eukar
16
Q
prokaryotic flagellum
A
thin protein filament
17
Q
archaea
A
extremophiles:
- methanogens (convert co2 to methane)
- halophiles
- acidophiles
- thermophiles
- hyperthermophiles
18
Q
mycoplasma
A
only prokaryote without a cell wall
19
Q
protists
A
unicellular
20
Q
differentiation
A
formation of specialized cells
21
Q
virus
A
intracellular obligate pathogen
- uses host machinery to make proteins
- bacteriophage: virus only infecting bacteria
22
Q
virion
A
more components than virus
- virus outside of host cell
- genetic material + capsid (protein coat)
- +/- envelope (outer lipid membrane)
extracellular virus capable of binding
23
Q
viroid
A
- RNA
- smaller than a virus
- no capsid just the genetic material
- plants
- doesnt produce proteins
24
Q
lysogenic viral infections
A
viral DNA inserts into the host cell’s genome (sits there - called a provirus) - can be excised and enter lytic phase when triggered
25
covalent bonds
driven by stability - full outermost shell
- polar (more reactive)
- nonpolar
26
noncovalent bonds
- ionic bonds
- hydrogen bonds (hydrogen covalently bound to electroneg atom)
- hydrophobic interactions
- van der waals (dipole - holds together neutral molecules)
27
bond strength
amount of energy required to breaka bond (kJ/mol)
- covalent stronger in solution than ionic
28
biochemicals
compounds produced by living organisms
29
functional groups
contain electronegative atoms - make shit polar - makes shit more reactive
- can be ionized (form charged molecules)
30
carbohydrates
- aka glycans
- function: energy storage, biological construction
- (CH20)n
- C-C single bonds backbone
- water soluble
31
carbs classification
- simple: monosaccharides (glucose, fructose, galactose) + disaccharides (maltose, lactose, sucrose)
- complex: polysaccharides (starches, fibers, glycogen)
32
glycosidic bond
covalent bond linking sugars (COC)
- to each other or lipids in the case of glycolipids
33
disaccharide
2 linked sugars
- oligo (few)
34
nutritional + structural polysaccharides
Nutritional
- energy stores
- glycogen (branched) and starch (branched and unbranched)
Structural
- cellulose (plant cell wall)
- chitin (exoskeleton)
- glycosaminoglycans (GAGs): extracellular space + connective tissue
35
lipids
soluble in organic solvent not water
36
cholesterol
cell memb + precursor of steroid hormones
36
proteins
- polypeptide chains
- amino acids linked via amide/peptide bonds
- amino acids will have amino + carboxyl group (connected by an alpha carbon)
37
cysteine
- thiol group
- sulfur oxidized --> covalent bond between two cysteine residues (forms disulfide bond which stabilizes proteins)
38
primary structure
sequence of amino acids
39
secondary structure
conformation of portions of polypeptide chains - maximizing hydrogen bonding
alpha helix or beta sheets
40
tertiary structure
3D conformation of entire polypeptide - eukar proteins will have 2 or more domains
41
homologous proteins
diff amino acid sequence but still same tertiary structure/ function
- actin and MreB
42
quaternary
multiple polypeptide chains/ subunits
43
molecular chaperones
bind to hydrophobic amino acids and help unfolded proteins achieve their 3D conformation
44
denaturation of a protein
disrupts secondary structure
45
nucleic acids
polymers of nucleotides
- 5 carbon sugar
- phosphate group
- nitrogenous base
46
dna vs rna
- OH at carbon 2 in rna
- rna is single stranded
47
purine
adenine + guanine
- two rings
48
pyrimidines
cytosine, uracil, thymine
CUT the PYE
49
thymine has a ____ that uracil does not
methyl
50
dna backbone
sugar phosphate backbone - forms helix
51
ribozymes
rna with catalytic activity
52
membrane carbohydrates
- glycoproteins: over 90% (glycosylation)
- glycolipids
53
glycosylation
process of attaching sugar to membrane protein
sugar attached to amino acid
- N-linkage: sugar attached to nitrogen (arginine + asparagine)
- O-linkage: attached to Oxygen from hydroxyl group (serine + threonine)
54
blood glycolipids
glycosidic bond attahching sugar to lipids
- Blood type A: have enzymes that add N-acetylgalactosamine
- B: enzymes add galactose
- AB: both enzymes
- O: no enzyme
55
factors dicatting proetin movement
- protein size
- membrane viscosity
- membrane skeleton
- neighbouring proteins
- extracellular interactions
56
RBC membrane skeleton proteins
- spectrin: major component internal membrane skeleton (attached to membrane surface via ankyrin) - linked to other cytoplasmic proetins too
57
western blot
chemical SDS denatures proteins and adds a neg charge
- proteins get separated by size on a gel (polyacrylamide gel electrophoresis - PAGE)
- primary antibody binds to antigen (protein); secondary antibody with enzyme that produces fluorescence binds to primary antibody - immunostain
58
facilitated diffusion
channel
carrier
59
net flux
influx - efflux
60
osmosis
movement of H2O across a semipermeable membrane from low SOLUTE concentration to HIGH
61
osnolarity
[solute] in solution
- hyperosmotic: more solute, less free water
- hypoosmotic: less solute, more water
62
turgor press
water pressure inside cell - pushes the plasma membrane against the cell wall
63
plasmolysis
no water - cell shrinks (hypertonic solution)
64
Aquaporins
- 4 subunits
- Each subunit has central
channel (Lined by hydrophobic a.a.)
- passive facilitated diff
65
channel gating mechanisms
- voltage gated (cell membrane reaching specific amount of voltage triggers opening)
- stretch-gated (tension gated)
- phosphorylation gated channel (signal triggers phosphorylation)
- ligand gated channel (ligand binds to receptor site)
66
channel states
open, inactivated, closed
67
bacterial KcsA potassium channel
has a selectivity filter (8 C=0 groups and forms a 3.0 A ring in between that only potassium (2.7A) can pass through)
68
carrier proteins
principle mode of passive transport for polar organic solutes (glucose, amino acids)
- rate depends on concentration gradient and number of transporters
69
___________ gradients are generated by active transport
electrochemical (gradient stores potential energy)
- using ATP hydrolysis, light, electron transport, flow of substances going down gradients
70
active trasnport
- primary - use ATP directly (transport protein is both transporter and enzyme since it catalyzes the hydrolysis of ATP; p type pump if it uses atp hydrolysis)
- secondary - use ATP indirectly
71
electroneutral (active transport) pumps
no overall change in cell's electrical properties
- parietal cell H+/K+ ATPase: stomach proton pump; acidifies stomach; pumps two protons into stomach in exchange of two K+ in - charge stays same
72
electrogenic (active transport) pumps
causes change in electrical properties of cell
- Sodium potassium pump - 10 membrane spanning helices - conformational changes E1
&2 change affinity for ions
73
Co-Transport
using existing ion gradients for transport
secondary active transport:
- symporter
- Antiporter (exchanger)
74
bioelectricity
electrical currents and potentials generated by all living cells
75
resting membrane potential
- -70 mV
- most important ion in RMP: K+
76
depolarization --> action potential
+40 mV
77
AP Propagation
- unidirectional + don't lose strength/intensity
- speed of neural impulse is greater wth: more axon diameter + myelin
78
nodes of ranvier
voltage gated sodium channels - only site where action potentials can be generated - saltatory conduction
79
mitochondria additional roles
- atp production
- regulation of innate immunity
- calcium homeostasis
- apoptosis
- stem cell regulation
80
high proton concentration in _____ of mitochondria
intermembrane space
81
matrix
- krebs cycle enzymes
- mitochondrial dna (maternally contributed, encodes for 13 proteins)
- ribosomes
82
ETC and ATP synthase
on inner membrane
83
how are the other mitochondrial proteins transported from outside of mitochondria
TOM (translocase of outer membrane) and TIM (translocase of inner membrane)
84
glycolysis
cytoplasm
- 2 pyruv, 4 atp, 2 nadh
85
atp structure
adenine + ribose + 3 phosphate
86
electron shuttles
- NAD+: nicotinamide adenine dinucleotide - derived from vitamin B
- FAD+: flavin adenine dinucleotide
87
Pyruvate _____ to Acetyl CoA
decarboxylated
88
fermentation
- cytosol
- forms lactate
- NAD+ regenerated from glucose
89
main source of energy for cells
Krebs cycle (input: oxidized acetyl CoA)
- Products: 3 NADH (each equals 3 atp), 1 FADH2 (=2atp), 1 GTP (=1atp)
net gain
- net gain: 12 ATP
90
pathways that could feed into krebs
- fatty acid cycle: contributes acetyl CoA
- catabolism of amino acids
91
glycerol phosphate shuttle
DHAP (dihydroxyacetone) takes electron from cytosolic NADH and leads to the formation of glycerol-3-phosphate % NAD+ (will takes the electrons across the mitoch)
- G3PDH (glycerol-3-phosphate dehydrogenase) transfers electron to FAD+
92
cellular respiration
glycolysis + krebs + oxidative phosphorylation
93
oxidative phosphorylation
2 part process (etc + chemiosmosis)
94
redox potential (oxidation-reduction potential)
transfer of electron between a pair causing a charge separation
95
reducing agents ranked according to ______
electron transfer potential
96
electron carriers found in different complexes within etc
1. flavoproteins: flavin mononucleotide created by the binding of proteins to FAD (eg. NADH dehydrogenase (complex1)& succinate dehydrogenase (complex2))
2. cytochromes: heme groups with Fe or Cu metal ions - (3 types: a,b,c)
3. copper atoms: 3 in a single protein complex (alternate between Cu2+ and Cu3+)
4. ubiquinone (coenzyme Q): lipid soluble molecule + made of five-carbon isoprenoid units
5. iron-sulfur proteins: Fe linked to sulfide ions to form iron-sulfide centers (not heme groups)
97
carrier arrangement
arranged in order of increasing +ve redox potential
98
proton pump other functions
- takes up adp and p
- takes up calcium for mitochodnrial fusion
99
tissue types
- nervous
- connective
- epthelial
- muscle
100
basement membrane functions
- structural support
- tumour invasion
- cell behaviour
- angiogenesis (blood vessel development)
101
extracellular matrix proteins
more fibrous
102
extracellular matrix molecules
- adhesive proteins (hold cells togther and form organized tissue) - integrins + cadherins + selectins + IgSF
- structural proteins (tensile and compressive strength) - elastin, keratin, collagen
- proteoglycans (fibronectin and laminin)
103
collagen
- produced by FIBROBLASTS
- glycoproteins
- only in ECM - most abundant protein in body
- type 1 - most common, bone skin tendon
- type 2: cartilage
- type 4: basement membrane (non-helical + terminal globular domains, lattice)
- 3, triple helix of alpha chains
- hydroxylation of proline and lysine creates stability - lack causes scurvy
- staggered alignment
104
tendon collagen
parallel, lined up same way
- cornea ones are arranged perpendicular - prevents refraction + increases tissue transparency
105
proteoglycans
- have amino sugar
- glycosaminoglycan
- function: space filler, cushioning, hydration
- repeating disaccharide structure ABAB
- acidic + neg charge cuz of amino sugar --> interacts with water and ions - gellike
- found in basement membranes + cartilage (hydration)
- eg: fibronectin and lamanin
106
fibronectin
- proteoglycan
- made of 2 polypeptide chains linked by disulfide bonds
- many different binding domains - so adds to collagen support framework and attaches cell to ecm
- role in development of nervous system - informs movement and differentiation of neural crest cells
- role in formation of salivary gland
107
laminin
- proteoglycan
- made of 3 polypeptide chains linked by disulfide bonds
- informs movement and differentiation of neural crest cells
- Strengthens basement membrane
108
collagen and laminin connected by
entactin
109
_____ form the basic insoluble framework of the ECM
collagen fibers (laminins form a parallel network)
110
________ degrade ECM components
Matrix metalloproteinases (MMP)
111
ECM dynamic properties
spatially (ecm fibrils can stretch several times their normal length) and temporally (continual degradation and reconstruction)
112
integrins
- most important cell surface receptor (connects to ecm)
- glycoproteins
- alpha and beta chain (heterodimer)
- 2 confromations (bent is inactivated, upright is activated)
- talin binds to integrin and anchors cell to ecm and actin cytoskeleton (actin polymerization)
- functions : adhesion to ecm and other cells + signal transduction inside-out and outside-in (eg. talin and cytoplasmic tyrosine kinases (FAK-src) - phosphorylation)
- RGD amino acid sequence - binds to cell, blood, ecm, proteoglycans
- prevent platelet aggregation where not needed
113
Key cellular protein involved in Cell-
ECM adhesion
integrin
114
arrangements of integrin
- focal adhesions (macromolecular assemblies forming mechanical links between intracellular actin bundles and the ECM); fxn: ahesion and migration
- hemidesmosomes: linkage between epithelial cells and basement membrane - keratin and cytoplasmic plaques
115
normal cells
integrin-binding
- malignant are integrin-independent
116
talin
anchors cell to ECM and actin cytoskeleton - binds to integrin, causing binding to collagen (ECM) + involved in mobility (actin will pull to whereveer cell is needed to move)
117
mechanotransduction
moveement of ecm around cell causes cell to respond too
118
cadherin
- glycoproteins
- join cells of similar type togetehr
- calcium dependent
- loss associated with malignancy
- give cells tensile strength - prevent from breaking when stretched - hold on to them
- form: adherens junctions (link cells via actin cytoskeleton; protein plaques connect cadherin to actin) and desmosomes (demoglein and desmocollin bind indirectly to intermediate filaments of the cytoskeleton)
119
adhesion molecules
- integrins
- cadherins
- selectins
- IgSF
120
selectins
- glycoproteins binding specific oligosaccharides (L, E, P selectins)
- small intracellular and large extracellular portion (membrane-spanning)
- locations: platelets, leukocytes, endothelial cells
- functions: cell-cell adhesion + signal transduction
121
immunoglobulin
- have Ig domain
- cell surface proteins or soluble (antibody)
- functions: cell recognition, binding, adhesion, neuronal growth and circuitry
122
pemphigus vulgaris
antibodies attack desmoglein
123
tight junctions
seal extracellular space, seal adjacent plasma membranes
- major proteins: claudins (adhesion, forms the junction) and occludins (selective permeability)
124
gap junctions
intercellular communication
- connect adjacent cells allowing for rapid communication
- connexin (has four transmembrane domains) subunits together form connexon (multi-subunit complex)
125
leucocyte recruitment after wound
- selectins
- integrins
- IgSF
126
Endomembrane System
- Endoplasmic reticulum (ER)
- Golgi apparatus
- Lysosomes
- Endosomes
- Vacuoles (plants)
protein synthesis and metabolism
127
constitutive mode of secretion
discharged continuously - secretory vesicles
128
SER functions
- Steroid hormone synthesis in endocrine cells
- Detoxification in liver (Oxygenases, Cytochrome P450 family)
- Calcium storage and regulated release
129
free reibosomes get proteins to
nucleus mitoch peroxisome
130
synthesis of secretory, lysosomal, plant vacuolar proteins
amino acid signal sequence (6-15 hydrophobic amino acid residues) in N- terminal portion of polypeptide determines synthesis site
- nascent polypeptide tells ribosome where to go
- Signal hypothesis: Proteins have built in “address codes”
- SRP (using gtp) takes it to ribosome to translocon
131
tail anchored proteins
no signal sequence + synthesized in cytoplasm
132
ER associated degradation
UGGT checks if protein has folded correctly (conformation sensing enzyme) - tags misfolded protein with glucose, removes mannose - later destroyed by proteasomes
