Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Cell Bio (final)- test 1 +new > Lectures 2-12 (test 1) > Flashcards

Lectures 2-12 (test 1) Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

4 types of macromolecules

A

lipids, proteins, polysaccharides, nucleic acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are lipids

A

heterogeneous structure, hydrophobic (ex phospholipid)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Lipid: fatty acid vs triacyglycerols vs phospholipids

A

fatty acid: carboxylic acid w/ aliphatic chain, which is saturated (straight) or unsaturated (bent, bc of double bond)
triacyglycerols: made of 1 glycerol & 3 fatty acids
phospholipids: hydrophilic head (phosphate group+glycerol) & 2 hydrophobic tails (fatty acids)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what have aromatic rings (lipids)

A

steroids (multiple rings) & terpenes (1 ring)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

define amphipathic. example?

A

having both hydrophilic & hydrophobic parts; phospholipid (makes up PM)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

PM consists of

A

2 layers of oppositely oriented phospholipid molecules; heads exposed to liquid, tails into middle of membrane (cholesterol must be here)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are polysaccharides

A

(sugars) long-chain polymeric carbohydrates composed of monosaccharide units bound together by glycosidic bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are disaccharides

A

2 monosaccharides joined by glycosidic bond (ex: maltose = glucose + glucose; lactose = galactose + glucose)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what can be storage or structural molecule

A

polysaccharides (store starch in plants; glycogen in muscles of naimals)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is cellulose considered

A

structural polysaccharide of cell wall (repeating glucose units)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is chitin

A

long-chain polymer of N-acetylglucosamine (main component of insect exoskeleton)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what does protein shape matter for

A

protein shape matters for function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is an amino acid

A

organic molecule w/both an amino group & carboxyl group, w/variable side chain (monomer for proteins)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how many amino acids make up protein

A

20

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

types of side chains

A

Nonpolar (hydrophobic), polar side chains (hydrophilic), electrically charged side chains (hydrophilic; - = acidic, + = basic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are amino acid polymers

A

polypeptides (peptide bonds hold together chain of amino acids)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

4 levels of protein structure

A
  1. primary: sequence of amino acids
  2. secondary: alpha helices & beta-strands (regions stabilized by hydrogen bonds)
  3. tertiary: subunit/folded shape; overall shape of polypeptide resulting from interactions between amino acids
  4. quaternary: overall structure resulting from aggregation of more than 1 polypeptide subunits
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

example of quaternary structure

A

hemoglobin (4 heme subunits together)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what are nucleic acids

A

macromolecules that exist as polymers called polynucleotides (DNA & RNA); monomers are called nucleotides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

structure of nucleotide

A

a nitrogenous base, 5 carbon sugar, 1 phosphate group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

2 families of nitrogenous bases

A

pyrimidines (1 ring) & purines (2 rings)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

DNA vs RNA

A

Deoxyribonucleic acid (cytosine, guanine, thymine, adenine)
Ribonucleic acid (cytosine, guanine, uracil, adenine)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

DNA structure

A

2 polynucleotide chains that coil around each other to make double helix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

nucleotides are joined to one another by what bonds

A

phosphodiester bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what end of chain has phosphate? sugar?

A

5’ end has phosphate group
3’ end has sugar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what are steps of taking info from genes to make proteins

A

Transcription: RNA polymerase uses DNA template to make pre-mRNA
Translation: ribosome makes protein (polypeptide) from mRNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what could cause sickle-cell disease

A

a single amino acid substitution in hemoglobin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

proteins are

A

chains of amino acids with 3D structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is central dogma

A

DNA –>(transcription -in nucleus)–> RNA –>(translation -in cytoplasm)–> Protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

membranes of nucleus

A

Inner and outer membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what is compact DNA called

A

chromatin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

what encodes ribosomal RNAs

A

nucleolus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

what catalyzes chemical reactions that synthesize RNA from DNA template

A

RNA polymerase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Different types of RNA polymerases

A

RNA polymerase I: rRNA genes
RNA polymerase II: mRNA, miRNA, snRNA, snoRNA genes
RNA polymerase III: tRNA & 5S rRNA genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

what is in the active site of RNA polymerase

A

2 DNA strands & RNA strand (2 DNA strands form helix at top, RNA polymerase separates the 2 DNA strands in middle & builds RNA strand, 2 DNA strands come back together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

what is the TATA box

A

DNA sequence of T & A nucleotides (30 nucleotides b4 transcription start site) -TATA binding proteins recognize the TATA box

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

RNA Polymerase II requires what proteins? what do they do?

A

General transcription factors; they start transcription

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Where does RNA polymerase & general transcription factors assemble

A

at promoter (TATA box)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

what is bigger: gene or protein it makes

A

gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

how does mRNA leave nucleus

A

nuclear pore complex (controls export and import into nucleus)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What do ribosomes do

A

read mRNA & translate info into polypeptide (2 subunits trap mRNA inside, ribosome reads & translates into amino acid chains)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

what is codon

A

3 nucleotides = 1 amino acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Which ribosome subunit has catalytic site? what does it do?

A

large subunit; makes new peptide bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

what does ribosome small subunit do

A

finds mRNA strand & ensures each codon pairs w/anticodon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

what does tRNA do

A

transfer RNA translates mRNA into amino acid (has anticodons & brings matching codons to mRNA trapped in ribosomes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

what is the start codon

A

methionine (AUG)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

what is translation termination factor

A

a protein that stops translation (UAA, UAG, UGA)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

pros of bacteria not having nucleus

A

proteins made faster

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

what does RNA splicing acheive

A

removes untranslated regions from mRNA (splices out introns)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Introns vs exons (mRNA)

A

Introns: region in gene that doesn’t remain in final mature mRNA (in pre-mRNA & spliced out)
Exons: RNA that codes for proteins (stays in mature mRNA to be exported)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

what does spliceosome do

A

cut exons & reconnect them to produce mRNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What does splicing allow us to do

A

encode multiple proteins in a single gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

T or F all cells make lipid

A

true, some more than others

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

what is TAG

A

triacylglycerols (glycerol & 3 fatty acids)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

what can TAG be made from? what does this?

A
  1. Acyltransferases make TAG from monoacylglycerols (cut fatty acid from 1 molecule & paste in another molecule/transfer of fatty acids)
  2. Glycerol-3-phosphate make TAG
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

what are acyltransferases

A

enzymes that move fatty acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Where is TAG made

A

smooth ER

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

where does TAG accumulate

A

lipid droplets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

what are lipid droplets? located where?

A

storage organelles; between PM of ER (they are in the tails of the phospholipids)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

what membrane do lipid droplets have

A

single membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

what assists lipid droplet budding from ER

A

seipin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

describe structure of lipid droplet

A

hydrophobic core of lipids, phospholipid monolayer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

what are perilipins

A

family of proteins that coat lipid droplets (on cytoplasmic side, outside)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

3 steps to make lipid droplet

A
  1. TAG synthesis & lens formation (cell separates 2 layers of ER membrane)
  2. emergence & nascent lipid droplet formation (still attached)
  3. lipid droplet budding & growth (cleaved, free to move)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

where does TAG synthesis occur (step 1 of LD formation)

A

between the smooth ER bilayer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

What facilitates the budding of lipid droplet (step 2 of LD formation)

A

Seipin is recruited to lens structure (beginning of LD) & facilitate growth out towards cytoplasm - w/o seipins, LDs would form in & out of ER

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

what side does budding of LDs happen towards

A

cytoplasm side (seipin push LDs this way)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

How does LD grow (step 3 of LD formation)

A

bud from ER & grow through fusion (w/other LDs) or local lipid synthesis (making more TAG)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

what do LDs do in cytoplasm

A

fuse/interact w/ other organelles via membrane proteins (mitochondria make energy out of lipids)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

What is the branchpoint between store TAG & making membrane lipids

A

Phosphatidic acid (smallest phospholipid)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

how to manipulate phosphatidic acid to become: TAG vs phospholipids

A

TAG: remove phosphate group
Phospholipids: keep phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

where are the enzymes kept that metabolize phospholipids

A

in all membranes (never in cytosol); different organelles have diff phospholipids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

structure of PIP2

A

2 fatty acids, glycerol, 3 phosphate groups (2 extra specific to PIP2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

3 kingdoms

A

bacteria, archaea, eukaryotes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

What does bacterial cell keep DNA in

A

nucleoid, in cytoplasm, compact structure of folded DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

what do bacterial & archaeal cells lack that eukaryotes have

A

internal membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

What does plant cell have that animal cell does not

A

cell wall, vacuole, chloroplast, granum (stack of thylakoids)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

what provides energy for cells

A

mitochondria (TCA/Krebs cycle / electron transport chain -> makes ATP) & chloroplasts (photosynthesis / CO2+light=sugars)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

structure of mitochondria

A

inner & outer membranes, cristae (invagination of membrane), matrix (has mtDNA, enzymes, where KREBS cycle occurs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

chloroplast structure

A

3 membranes (outer, inner, thylakoid membrane), stroma (matrix which has cpDNA, enzymes), thylakoids (stack = granum; photosynthesis, chlorophyl)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

what is endomembrane system? steps?

A

synthesis of proteins for variety of cellular destinations; steps: mRNA leaves nucleus, translates into protein in ribosomes of ER, goes to Golgi, sorted or secreted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

structure of ER

A

tubular membranes & flat sacs, cisternae & lumen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

Rough Er vs Smooth ER (function)

A

rough: ribosomes, synthesis of proteins
smooth: synthesis of lipids & steroids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

Golgi & secretory vesicles

A

vesicle enters Golgi at cis, leaves trans side; sugar coats on vesicles allows for protein to sort by coat

85
Q

lysosome

A

enzymes degrade/digest molecules, acidic (low pH), inside membrane is glycosylated

86
Q

what is the peroxisome

A

breaks fatty acid chains, catalase converts hydrogen peroxide into water & oxygen, works with oxidizing agents in cell

87
Q

Extracellular matrix vs cell wall

A

both outside PM
Extracellular matrix: collagen fibrils, proteoglycans (proteins w/many disaccharide units)
Cell walls: cellulose (polysaccharide)

88
Q

integrin connects what

A

cytoskeleton & extracellular matrix (collagen, laminin, proteoglycans)

89
Q

what does ECM do

A

glue cells and tissues

90
Q

different classes of lipids in membrane

A

phospholipids, glycolipids, sterols

91
Q

lipid bilayer is

A

fluid & asymmetric (phospholipids diffuse laterally /move around side they are on, transverse diffusion/flip-flop, rotate (proteins block these movements)

92
Q

what are translocases

A

proteins that move phospholipids between layers & maintain lipid asymmetry

93
Q

types of translocases & function

A

Flippase: moves lipids from outside to inside
Floppase: moves lipids back outside
Scramblase: moves lipids both ways to ensure asymmetric

94
Q

what was FRAP used to test

A

movement of membrane proteins

95
Q

what must membrane proteins have

A

hydrophobic amino acids (pass through membranes)

96
Q

types of membrane proteins

A

integral (single or multi pass)
peripheral (on one side of PM, anchored to integral membrane protein)
lipid-anchored (on one side of PM, bind to fatty acid in membrane)

97
Q

membrane proteins mediate what? example

A

cell adhesion & cell-cell communication; cadherin-cadherin binding in intercellular space keeps cells together/catenin is part inside cell)

98
Q

what are integral monotopic proteins

A

rare proteins that are only on one side of membrane

99
Q

how are lipid-anchored proteins bound to fatty acid? example?

A

covalent bond; trehalase (cuts trehalose into 2 glucose molecules)

100
Q

what proteins & lipids are glycosylated

A

outside the membrane

101
Q

what are 2 types of glycosylation

A

N-linked glycosylation & O-linked glycosylation

102
Q

what is process of glycosylation

A

carbohydrate is covalently attached to target macromolecule

103
Q

how can solutes cross membrane

A

simple diffusion, facilitated diffusion, active transport

104
Q

what molecules pass freely vs not

A

Pass freely: Small uncharged molecules (oxygen, carbon dioxide
Don’t pass freely: Large polar molecules/ions (water, hydrogen, glucose, amino acids - all required active transport)

105
Q

what is simple diffusion

A

unassisted movement of solute following concentration gradient

106
Q

what is facilitated diffusion

A

protein mediated movement along concentration gradient (no ATP used) (ex: glucose)

107
Q

what are 2 major protein types that mediate facilitated diffusion

A

channels (pores) & carriers (conformation change = solute moves)

108
Q

types of carrier proteins (3)

A

uniport (move 1 solute), symport (move 2 in same direction), antiport (move 2 in opposite directions)

109
Q

3 types of channel proteins (transmembrane channel)

A

ion channels (specific to ion), porins (not specific), aquaporins (h2o only)

110
Q

what are ion channels

A

transmembrane proteins that allow rapid passage of specific ions

111
Q

what can open ion channel (4 types)

A

voltage, ligand, temperature, pressure

112
Q

what do ligand-gated ion channels convert

A

convert chemical signal into cell

113
Q

what does voltage-gated channel transmit

A

transmit signal in wave through nervous system (amplifies signal)

114
Q

what can have porins

A

mitochondria, chloroplasts, bacteria (allow rapid passage of various solutes)

115
Q

what is ATP

A

main energy storage molecule, negatively charged, made in mitochondria, can’t pass through membranes (Adenosine + sugar + 3 phosphate groups)

116
Q

what is a voltage-dependent anion channel (VDAC)

A

mediates exchange of negatively charged metabolites (ex ATP from mitochondria to cytoplasm)

117
Q

what does movement against concentration gradient require

A

ATP

118
Q

indirect vs direct active transport

A

Indirect: symporters & antiporters; one solute follows conc gradient, this saved energy is used to move another solute against gradient
Direct: ATP used directly to pump a solute across membrane against its electrochemical gradient (protein hydrolyzes ATP)

119
Q

what uses both direct & indirect active transport

A

Amino acid absorption
Indirect: amino acid symporters move amino acids into enterocytes
Direct: ATPase pumps maintain ion gradients

120
Q

what are transport ATPases

A

ATP-driven pumps (they hydrolyze ATP to ADP & P, use the energy released to pump ions or other solutes across membrane)

121
Q

Types of transport ATPases

A
  1. P-type pump: phosphorylate themselves during pumping cycle (maintain electrochemical gradients)
  2. ABC-type ATPases: ATP-binding cassette transporters, mediate ATP-powered translocation of many substrates across membranes
  3. Vacuolar-ATPase: pumps H+ ions to increase acidity (2 rotary motors)
  4. F-type ATPases: ATP synthase (moves ions with concentration gradient to produce ATP)
122
Q

P-ATPases to know (3):

A
  1. Ca2+ ATPase/pump / Moves Ca2+/H+: keeps [Ca2+} low in cytosol, in sarcoplasmic reticulum or PM, in muscles
  2. Na+/K+ ATPase / Na+/K+: maintains membrane potential (-60mV), in PM, in animals
  3. H+/K+: pumps H+ to acidify stomach, in PM, in animals
123
Q

what does sarcoplasmic reticulum of muscle cells do

A

intracellular store or Ca2+; special type of ER that forms network of tubular sacs in muscle-cell cytoplasm (uses ATP to change conformation to move Ca2+)

124
Q

what is role of Na+/K+ ATPase

A

maintains electrochemical ion gradients in all cells (pumps 3 Na+ out / 2 K+ in)

125
Q

structure & function of Vacuolar-ATPase

A

has 2 motors, ATP-driven motor turns an axle which turns second motor (transmembrane part) that pumps protons across membrane, held together by linker; pumps H+ ions to increase acidity in certain organelles (ex lysosomes)

126
Q

function and structure of F-type ATPases

A

Function: ATP synthases; moves ions w/conc gradient to produce ATP; moves H+ along gradient to drive ATP synthesis (into mitochondrial inner membrane)
structure: 2 motors (connected by stator); intermembrane motor is powered by H+ flow, other motor is powered by ATP (in mitochondria)

127
Q

how does the motor inside the mitochondria in ATP synthase/F-type ATPase join ADP and P

A

joins together by force

128
Q

what are ABC-type ATPases

A

ATP-binding cassette transporters, mediate ATP-powered translocation of many substrates across membranes; heterodimers that hydrolyze ATP and change conformation (has 2 transmembrane domains, 2 ABC in cytoplasm

129
Q

what is ATP-binding cassette

A

conserved protein domain (all ABC transporters have a shared amino acid sequence in ABC domain)

130
Q

how does heterodimerization of ABC-ATPases affect solutes

A

more solutes can be moved

131
Q

2 types of metabolic pathways

A

Anabolic: make large molecules (require energy)
Catabolic: break large molecules (releases energy)

132
Q

Oxidation vs Reduction of organic molecules (resulting effects)

A

Oxidation: loss of hydrogen, gain of oxygen, loss of electrons
Reduction: gain of hydrogen, loss of oxygen, gain of electrons

133
Q

what are NAD & FAD

A

coenzymes of redox reactions & electron carriers
NAD+ & FAD accept electrons (become reduced) during catabolic steps
NADH & FADH2 donate these electrons to another reaction (usually anabolic, like synthesis of ATP)

134
Q

what is an important oxidizable substrates in energy metabolism? reasons?

A

glucose; its oxidation is highly exergonic (releases energy), many polysaccharides break into glucose (starch, glycogen, cellulose)

135
Q

what enzymes catalyze oxidation

A

ATP and NADH

136
Q

what is glycolysis

A

metabolic pathway that entails the oxidation of glucose molecules into 2 pyruvate molecules

137
Q

steps of glycolysis (3)

A
  1. prep & cleavage (glucose is phosphorylated twice by ATP, split)
  2. Oxidation & ATP generation (the 2 molecules are oxidized, energy is conserved as 2 ATP & 2 NADH molecules are produced)
  3. Pyruvate formation & ATP generation (the 2 molecules are converted into pyruvate & this makes 2 ATP)
138
Q

what is the net/end result of glycolysis

A

1 glucose –> 2 ATP & 2 pyruvate & 2 NADH

139
Q

summary/short steps of glycolysis

A
  1. add 2 phosphates & cleave
  2. oxidation & ATP made
  3. Make pyruvate & ATP
140
Q

what are disaccharides broken down into (what are the 3 monosaccharides)? They are converted into Glycolysis intermediates

A

glucose, galactose, fructose

141
Q

what are the disaccharides in Glycolysis

A

Lactose, maltose, sucrose

142
Q

what is the branchpoint between aerobic & anaerobic metabolism

A

pyruvate
If high [O2], PDH takes pyruvate; if low [O2], LDH makes lactate

143
Q

aerobic vs anaerobic metabolism

A

Aerobic: oxygen present, pyruvate -> Acetyl CoA (pyruvate oxidized, NAD+-> NADH, CO2 released, Acetyl CoA made)
anaerobic: lacks oxygen, pyruvate –> either lactate or ethanol & CO2 (NADH oxidized to NAD+)

144
Q

how do tumor cells metabolize glucose to lactate

A

w

145
Q

what is Warburg effect

A

done by tumor cells; perform anaerobic glycolysis, despite having available oxygen

146
Q

what is mitochondrial pyruvate carrier

A

it transports pyruvate into mitochondria (glycolysis happens in cytoplasm, TCA cycle happens in mitochondria, Acetyl-CoA enters TCA cycle)

147
Q

what does pyruvate dehydrogenase do

A

convert pyruvate into Acetyl-CoA (adds CoA & NAD+, removes carbon & NADH, releases energy)

148
Q

what are dehydrogenases

A

enzymes that remove a pair of hydrogen atoms from a substrate, oxidizing it

149
Q

what is the structure of pyruvate dehydrogenase? cofactor needed?

A

multiples of 3 subunits;
E1 metabolite binding sites
E2 core of complex
E3 intermediate enzyme;
E1 needs vitamin B1 derivative as cofactor

150
Q

what molecule is used in Glycolysis to store energy

A

ATP & NADH

151
Q

What are the names for Citric acid cycle

A

Citric acid cycle, Tricarboxylic acid cycle, Krebs cycle

152
Q

where does KREB cycle occur

A

matrix of mitochondria

153
Q

Steps of KREB cycle (very brief)

A
  1. Glycolysis (only step done in cytosol)
  2. Pyruvate oxidation
  3. Citric acid cycle
  4. Electron transport & Proton pumping
  5. ATP synthesis
154
Q

what is done in first step of KREB cycle

A

pyruvate converted to Acetyl CoA by Oxidative Decarboxylation (removal of carboxyl group & releases CO2)

155
Q

how does Citric acid cycle begin

A

entry of acetate as Acetyl CoA

156
Q

what are the products of TCA cycle

A

CO2, ATP, NADH, FADH2
(acetyl-CoA –> 3NADH + FADH2 + ATP + 2CO2)

157
Q

what plays a big role controlling citric acid cycle

A

oxoglutarate dehydrogenase (inhibited by its products, succinyl CoA & NADH, also inhibited by high energy charge in cell; activators: ADP & Ca2+)

158
Q

where does NADH bind in TCA cycle

A

anywhere on pyruvate dehydrogenase but the E1 subunit to inhibit the complex

159
Q

what is an allosteric regulator

A

substance that binds to site on an enzyme separate from the active site (where they bind to substrate); binding changes protein shape & activity (positive or negative feedback)

160
Q

what is common between citric acid cycle and electron transport chain

A

Succinate dehydrogenase (SDH) or respiratory complex II (it is a membrane protein)

161
Q

what does Citric acid cycle play central role in

A

catabolism of fats & proteins

162
Q

what is most fat stored as

A

triacylglycerols

163
Q

how does catabolism of triacylglycerols begin

A

hydrolysis to glycerol & free fatty acids

164
Q

how are fatty acids in TCA cycle

A

fatty acids linked to coenzyme A to form fatty acyl CoAs, which are degraded by beta-oxidation (catabolic process that generates acetyl CoA & NADH & FADH2, reduced forms)

165
Q

what free thing can be catabolized for energy

A

free amino acids

166
Q

what does protein catabolism begin with

A

Proteolysis: hydrolysis of peptide bonds linking amino acids in polypeptide chain (enzymes used to do this are proteases - chop bonds)

167
Q

all pathways for amino acid catabolism eventually lead to …

A

pyruvate, acetyl CoA, or other intermediates in citric acid cycle (amino acids give up carbons for KREB cycle)

168
Q

cataplerotic vs anaplerotic pathways

A

Cataplerotic pathways provide precursors for biosynthesis (take apart TCA intermediates for this)
Anaplerotic pathways regenerate TCA intermediates

169
Q

what feeds into TCA cycle

A

amino acids, sugars & lipids

170
Q

what are the products & play important role in electron transport chain

A

NADH & FADH2

171
Q

What is the goal of electron transport chain

A

use NADH & FADH2 to concentrate protons in intermembrane space (of mitochondria)

172
Q

What happens in outer mitochondrial membrane, intermembrane space, inner mitochondrial membrane, and matrix

A

outer mito membrane: glycolysis
intermembrane space: high [H+]
inner mito membrane: electrochemical potential generated here
matrix: NADH & FADH2 made here

173
Q

what does electron transport chain use for energy

A

electrons from NADH & FADH2 (H from NADH is removed & converted into 1H+ & 2e-)

174
Q

Electron transport chain for NADH

A

NADH->NAD+ -gives up 2e- to Complex I, pass 2e- to Coenzyme Q & pump out 4H+, go to Complex III, to Cyt C, to Complex IV, 2e- transferred to oxygen (make H2O)

175
Q

What are prosthetic groups (ETC)

A

electron carriers (associate closely with protein molecules); are large non-protein molecules embedded in protein (ex: iron-sulfur clusters)

176
Q

example of prosthetic group in electron transport chain

A

heme is prosthetic group in hemoglobin & is needed for oxygen binding

177
Q

what is Coenzyme Q

A

lipid-like carrier (aka ubiquinone)

178
Q

Electron transport chain for FADH2

A

Succinate gives FADH2 2e- (associated w/ Complex II), 2e- go to CoQ (no H+ pumped), go to Complex III, 2e- go to Cytochrome C & pump 4H+, 2e- go to Complex IV, go to water & pumps 2H+

179
Q

what is cytochrome C

A

small protein that serves as carrier of electrons; moves e- from Complex III to IV

180
Q

how many directions do electrons move? why?

A

single direction; bc of redox centers (electron carriers) are organized from low to high affinity

181
Q

what complex is a part of FADH2 & not NADH electron transport chain

A

Complex II

182
Q

summary of NADH & FADH2 electron transport chain pathways

A

NADH: C1, CoQ, C3, Cyt C, C4, O2
FADH2: C2, CoQ, C3, Cyt C, C4, O2

183
Q

structure of complex I (how are redox centers & H+ pump structured)

A

redox centers & H+ pumps are separated in complex (H+ pump is transmembrane; redox centers are attached on outer side)

184
Q

what must happen for Complex I to move H+

A

structural changes in Complex I direct H+ to move through translocation half-channels (aligning of half-channels allows H+ to move)

185
Q

in electron transport chain, are complexes apart or together

A

complexes are clustered together; form supramolecular assemblies/supercomplexes

186
Q

what powers ATP synthase

A

difference in [H+] on opposite sides of the inner mito membrane (motor squeezes ADP + P together = ATP)

187
Q

define apoptosis

A

programmed cell death

188
Q

what was an in class example of apoptosis/see a dying cell (animal?)

A

c. elegans (worm watched in vivo)

189
Q

what are methods to execute apoptosis

A

DNA degradation, corpse engulfment

190
Q

what can apoptosis do with tissues

A

clear connecting tissue & make arthropod joints (e.g. get rid of webbed feet)

191
Q

Differences between necrotic & apoptotic cells

A

Apoptotic have intact PMs, die neatly (shrinks, is eaten by another cell)
Necrotic cells spill their contents into neighbours

192
Q

What is the role of caspases in apoptosis

A

caspases (cysteine aspartate proteases) mediate proteolytic cascade that apoptosis depends on

193
Q

what do caspases do (apoptosis)

A

when activated, chop up strategic proteins in cell, use sulfur atom in cysteine to perform cleavage (cut proteins next to aspartate amino acids)

194
Q

Examples of initiator caspases vs effector caspases (apoptosis)

A

initiator caspases: Caspase 8 & 9
effector caspase: Caspase 3, 6, & 7

195
Q

what do initiator caspases do

A

being apoptosis by activating executioner caspases, which orchestrate apoptosis

196
Q

what are caspases synthesized as? how are they activated?

A

procaspases (inactive precursor); activated by cleavage (by another caspase through dimerization - apoptotic signal triggers assembly of adaptor-protein complex, it brings 2 procaspases close, they cleave/activate each other)

197
Q

how are executioner caspases activated

A

cleaved/activated by initiator caspases

198
Q

what amplifies apoptosis signal

A

cascade of caspase activations

199
Q

what does caspase-activated DNAse (CAD) do

A

catalyzes hydrolytic cleavage of DNA (CADs activated by executioner caspase, CAD cleaves DNA between nucleosomes)

200
Q

what are the 2 main activation pathways

A

extrinsic pathway: signaled from outside the cell
intrinsic pathway: signaled from mito inside the cell

201
Q

details of extrinsic pathway

A

Fas ligand on killer lymphocyte PM binds to Fas death receptor on target cell PM, activated Fas receptors on PM reveal death domains on receptor tails (in cell), bind & cluster small intracellular adaptor protein FADD, clusters of FADD recruit inactive initiator caspases which oligomerize, this large structure is called the death-inducing signaling complex (DISC), caspases cleave & activate, target cell is now apoptotic

202
Q

why is intrinsic apoptosis done/started? What is the intrinsic signal?

A

in response to developmental signals/injury (like DNA damage); release of Cytochrome C from mito into the cytoplasm is signal that activates intrinsic pathway activation

203
Q

details of intrinsic apoptosis pathway

A

binding of cytochrome c to Apaf1 adaptor protein in cytoplasm activates/exposes an oligomerization domain (CARD exposed to recruit more Apaf1) & caspase recruitment domain, Apaf1 recruits inactive caspase-9 monomer forming apoptosome, caspase-9 monomers are activated by dimerization (cleaving each other) –> apoptosis

204
Q

what is apoptosome? what apoptosis pathway is it assocaited with?

A

oligomerization of Apaf1 and caspases (Apaf1=apoptotic protease activating factor 1, activates caspases by oligomerizing into complex called apoptosome)

205
Q

what are inhibitors of apoptosis (IAPs)

A

caspase inhibitor proteins; they are defense against inappropriate caspase activation (bind & prevent activation of some procaspases)

206
Q

what are the main regulators of intrinsic pathway

A

Bcl2 proteins; pro-apoptotic Bcl2 proteins make holes into mito membrane, anti-apoptotic Bcl2 proteins inactivate pro-apoptotic Bcl2 (no holes made)

207
Q

what phagocytoses and digest apoptotic cells? What happens if cells are cancerous?

A

healthy neighbors apoptose dying cells; cancer cells induced apoptosis to healthy neighbors to make room for more cancerous cells

208
Q

what do caspases degrade

A

flippase that keeps Phosphatidyl serine inside cell (PtdSer must be outside for apoptosis to occur); normal cells recognize apoptotic cells bc they have PtdSer outside

209
Q

what is ferroptosis

A

intracellular iron-dependent form of cell death (distinct from apoptosis & necrosis); not enough iron + too many damaged phospholipids = Ferroptosis (characterized by accumulation of oxidatively damaged phospholipids/lipid peroxidation)

Cell Bio (final)- test 1 +new (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions