MCAT-Biochemistry/Biology Flashcards
1
Q
What are the four different tissue/cell types?
A
Epithelial
Muscle
Neuronal
Connective
2
Q
Epithelial tissue is classified according to and ______ of cells
A
Shape and arrangement
3
Q
Shapes of epithelial cells?
A
Squamous
Cudoidal
Columnar
4
Q
What are the arrangements of epithelial cells?
A
Simple
Stratified
5
Q
Do epithelial cells have a high turnover rate?
A
Yes
6
Q
What are the 3 main types of filaments that make up the cytoskeleton?
A
Microtubules
Microfilaments
Intermediate filaments
7
Q
What is epithelial tissue
A
Covers the surface of the body which contacts the environment
8
Q
What is the extra cellular material that separates all connective tissue?
A
Matrix
9
Q
What is connective tissues function?
A
Supports and connects all other tissues
10
Q
What are the 3 types of connective tissue cells?
A
Fibroblasts
Mast cells
Macrophages
11
Q
What are the two types of fibroblast cells?
A
Collagen based
Elastic
12
Q
Where are mast cells found and what is their function?
A
Near blood vessels and secrete various substances into the blood.
13
Q
What is the function of macrophages?
A
Specialized in phagocytosis of foreign particles pathogens.
Important in defense against infection.
14
Q
What are the 5 different types of connective tissue?
A
Blood and lymph Bone Loose connective Dense connective Cartilage
15
Q
What is the function of loose connective tissue?
A
Attaches epithelium to organs
Adipose tissue is an example
16
Q
What is the function of dense connective tissue?
A
Makes up tendons and ligands.
17
Q
What is the name for bone cells?
A
Osteocytes
18
Q
What are the three types of muscle tissue?
A
Skeletal muscle
Cardiac muscle
Smooth muscle
19
Q
Where is nervous tissue found?
A
Brain and spinal chord
20
Q
Skeletal muscle has what appearance?
A
Striated
21
Q
Cardiac muscle has what appearance?
How is it controlled?
A
Striated
Involuntarily
22
Q
Smooth muscle has what appearance?
How is it controlled?
A
Not striated, smooth
Involuntarily
23
Q
What do neurons do?
A
Transmit electrical impulses
24
Q
Glial cells have what function?
What is another name for glial cells?
A
Support, insulate and transport nutrients to neurons
Schwann cells
25
All cells in the soma have a _________ across all membranes?
Electric potential
26
The intercellular space has what kind of net charge?
Negative
27
The intracellular space has a high sodium or potassium concentration versus the extra cellular space?
Potassium
28
What is the resting potential of cells?
-70 mv
29
What system uses active transport to maintain electrochemical potential of cells?
Sodium potassium pump
30
What type of channels facilitate ion flow in and out of membranes down their concentration gradients?
Gated channels
31
An action potential is followed by what event?
Is the cell excitable during this time?
Refractory period
Depends on if it is an absolute or relative refractory period
32
What are microtubules made of?
Tubulin
33
Which of the three filaments of the cytoskeleton form the mitotic spindle?
Microtubules
34
What are the component proteins of microfilaments?
Actin and myosin
35
The nucleus contains what three structures?
Nucleolus
Nuclear envelope
Chromosomes
36
What is the function of the nucleus?
Sequesters DNA from enzymatic reactions in cytoplasm
37
Describe the rough endoplasmic reticulum
Attached to cytosolic side of the ER, is studded with ribosomes
38
What is the function of the smooth endoplasmic reticulum?
Plays a role in lipid synthesis
39
What is the function of peroxisomes?
Vesicles with digestive function. Breaks down fatty acids and amino acids. H2O2 is produced as a byproduct, is converted to alcohols and water.
40
Describe the function of the Golgi apparatus
Augment lipids and proteins and package into vesicles for delivery to extra cellular space.
41
Describe the role and functions of lysosomes
performs intracellular digestion. Aids in endocytosis via breaking down material from outside the cell
Contain enzymes that breakdown ALL biomolecules,
42
What does Avogadro law state?
Volume of a gas is directly proportional to number of moles of gas
At constant temperature and volume
43
What is the trend for the van der waals correction factors?
Increase in both correction factors values with increase in mass and complexity of structure
44
Graham’s law of effusion
Effusion rate is inversely proportional to the square root of the molecular mass of gas
45
Gases have substantial or negligible intermolecular/ attractive forces versus liquids and solids?
Negligible
46
What holds together a network solid?
Covalent bonds
47
What holds together a molecular solid?
Intermolecular forces
Example is solid H2O
48
Solvation shell of water stabilized what type of amino acids?
Charged
```
Aspartate
Glutamate
Lysine
Arginine
Histine
```
49
What are the charged amino acids?
```
Asp
Glu
Lys
Arg
His
```
50
What stabilizes primary structure of proteins?
Peptide bond
51
What is the primary structure of proteins?
Linear polymer
52
Types of secondary structures of proteins
Alpha helix
Beta pleated sheets
Coils and loops connections
53
What stabilizes secondary protein structures?
Backbone interactions composed of hydrogen bonding
54
What stabilizes tertiary structure of proteins?
Side chain interactions
Hydrophobic interactions
Van der waal forces
Disulfide bonds
55
Where do charged amino acid residues occur in tertiary protein structure?
On the outer part of protein exposed to water
56
In TLC what is RF
Rise of compound /length of tlc glass
57
Cation exchange resin has what kind of charge on the resin?
Negative
58
What kind of charge does anion exchange resin have?
Positive
59
If using cation exchange resin, if pH of mobile phase is lower than the isoelectric point of protein, will the protein be retarded on the stationary phase?
Yes
60
If using cation exchange resin and the pH of the mobile phase is higher than the isoelectric point of the protein, will the protein be retarded on stationary phase?
No, protein has a net negative charge, will be repelled by the anionic charge of resin.
61
If using a anionic exchange resin, if pH of mobile phase is lower than the isoelectric point of protein, will protein be retarded on the stationary resin?
No, protein will have net positive charge and will be repelled by positive charge on resin.
62
What kind of stationary phase does an HPLC have?
Will polar or non-polar compounds elute first?
Non-polar
Polar
63
Which particles elute first on size-exclusion chromatography?
Large particles
64
Affinity chromatography is used to separate what?
Proteins and nucleus acids
65
How does affinity chromatography work?
Recombinant proteins have affinity tags (HIS tags) which bind to nickel bonded to stationary phase. Elute isolated protein via a buffer wash.
66
Gas chromatography separates compounds based on what?
Volatilities
More volatile species elute faster
67
Simple distillation works best for what scenarios?
Removing trace impurities
Separating mix of liquids with a significant difference in boiling points
68
Fractional distillation works best for what scenarios?
Mixture of liquids with similar boiling points.
69
What two atoms have naturally occurring isotopes in relative abundance dance that allow for identification via mass spec?
Cl yields a main peak and a second less abundant peak 2 amu heavier with 1/3 the abundance
Br yields 2 major peaks with equal abundance
70
Maximum wavelength is proportional to what via uv-vis spec?
Conjugation
71
What is the IR stretch for a carbonyl group?
1680-1730
72
What is the stretch for an OH group?
3200-3600 broad
73
What is the IR stretch for a carbon carbon triple bond?
2100-2300
74
What is the IR stretch for a N-H?
2500-3100
75
What is the proton NMR shift for a aromatic proton?
6-8 ppm
76
What is the proton NMR shift for a alkene proton?
5-6 ppm
77
What is the proton NMR shift for a alcohol proton?
2-5 ppm
78
What is the proton NMR shift for a carboxylic acid proton?
10-13 ppm
79
What is the proton NMR shift for a aldehyde proton?
9-10 ppm
80
What is the proton NMR shift for a proton next to an electronegative atom?
2.5-4
81
The secondary enzyme used in an ELIZA bonds where?
The constant region of the antibody that is specific to the antigen interested in.
82
How does a radio-immuno assay differ from an ELIZA?
Uses radio labeled antigens to detect antibodies.
83
What are the different types of blotting and how do they differ?
Southern- detects DNA
Northern- detects RNA
Western- detects proteins- works similar to ELIZA
84
What does the term transformation mean?
The process of implementing modified plasmids into bacterial cells via heat shocking.
85
What is cDNA?
Produced using mRNA ( post-transcriptionally modified) via Reverse Transcriptase
86
Potassium ions move from where to where via potassium leak channels?
Move from intracellular to extra cellular down concentration gradient.
87
Sodium ions flow from where to where via voltage gated sodium channels?
Sodium flows from extra cellular space to intracellular space down its concentration gradient. It depolarizes the cell during an action potential to positive values.
88
What do Schwann cells create?
The myelin sheath
89
Are myelinated parts of axons able to conduct action potentials?
No, no ions are able to penetrate in or out of the myelin sheath.
90
Where do action potentials occur on an axon?
Nodes of ranvier
91
Outline the 3 steps that occurs during the repolarization after an action potential.
1. Voltage gated sodium channels close
2. Voltage gated potassium channels open (K flows out of the cell) until the electric potential of the overshoots resting potential and acquires valley of -90 mv. Then they close.
3. Na/K pump along with with potassium leak channels raise the electric potential of cell from -90 mv to resting potential.
92
Is a cell capable of an action potential during the absolute refractory period?
No
93
Is the cell capable of conducting an action potential during the relative refractory period?
Yes, but a greater stimulus is required because the cell is hyper polarized and is attempting to lower the electric potential from -90 mv to resting potential.
94
Where do electrical synapses occur?
Cardiac muscle and smooth muscle
95
What structure facilitates the spreading of action potentials in electrical synapses?
Gap junctions
96
What does a chemical synapse do?
Converts an action potential to a chemical signal (neurotransmitter).
97
What kind of voltage gated ion channels are utilized in the presymnaptic knob to release NT’s?
Voltage gated Calcium
98
What type of NT depolarizes a cell?
Excitatory
99
What type of NT hyperpolarizes a cell?
Inhibitory
100
Can a single synapse initiate an action potential of a post synaptic neuron?
No, an action potential is generated an determined via the summation of all synapses acting on the post synaptic neuron.
101
What is temporal summation?
Build up of Epsp’S or Ipsp’s from a singular neuron
102
What is the term Spatial summation
The summation of all pre synaptic neurons acting on a post synaptic neuron.
103
Muscles and glands carry out integrative info from CNS and are called?
Effectors
104
The PNS is responsible for carrying out what functions?
Sensory and motor function
105
What type of neurons carry info toward the CNS?
Afferent neurons
106
When the parasympathetic system is activated the body is prepared for?
Rest and digestion
107
When the sympathetic system is activated the body is prepared for?
Fight or flight
108
The somatic division of the PNS deals with?
Conscious voluntary movement of skeletal muscle.
109
The autonomic division of the PNS deals with?
Non-conscious, involuntary processes such as digestion, metabolism and perspiration.
110
List the 4 components of the CNS
Spinal chord
| Brain
111
List the sub divisions of the brain
Forebrain
Mid brain
Hindbrain
112
Equilibrium occurs when delta G equals?
0
113
What does the term spontaneous reaction mean?
It has a negative delta G value
One that occurs without a net addition of energy
114
How would someone produce more transition state intermediates of a reaction?
Lower the activation energy barrier of the reaction.
115
How does a catalyst lower the Ea of a reaction?
It stabilizes the transition state intermediate
It makes the existence of the intermediate more thermodynamically favorable
116
Enzymes have what kind of role?
Kinetic role
117
What amino acid is a readily available proton donor AND acceptor at physiological pH?
It is prevalent in the active sites of enzymes.
Histidine His H
118
Polar amino acids are capable of what?
Hydrogen bonding
119
What is the abbreviations of phenylalanine?
Phe
| F
120
What is the abbreviations of tryptophan?
Trp
| W
121
What is the abbreviations of asparagine ?
Asn
| N
122
What is the abbreviations of glutamine?
Gln
| Q
123
What are the two sulfur containing amino acids?
C
| M
124
Disulfide bonds can form only on this amino acid?
Cys
125
What are the two types of covalent bonds formed in proteins?
Peptide bonds and disulfide bonds
126
What is the function of a protease?
Cleave peptide bonds
127
What is the name of the resulting residue when two cysteine residues form a disulfide bond?
Cystine
128
What two properties of proline cause issues in polypeptide chains?
1. When introduced into a polypeptide it no longer has an amino hydrogen, thus does not participate in hydrogen bonding
2. The conformational strain of the ring r group kinks the poly peptide chain
129
What amino acid is never found in alpha helixes?
Proline
130
Tertiary structure of proteins is governed by what effect?
Hydrophobic effect
131
Denaturing agents destabilize what bonds?
Hydrogen bonds
132
How do quarter art disulfide bonds differ from tertiary?
Quat ds bonds form between two different peptide chains.
133
What does a phosphates do?
Removes a phosphate group from a molecule
134
What does a phosphorylase do?
Adds a phosphate group to a molecule from inorganic phosphate
135
What does a kinase do?
Transfers a phosphate group to a molecule from a high energy carrier (ATP)
136
What does a lyase do?
Breaks chemical bonds via methods other than hydrolysis or oxidation.
Ex: pyruvate decarboxylase
137
What does a ligase do?
It forms chemical bonds
138
What does a hydrolase do?
It hydrolyzes chemical bonds
Ex: ATPase
139
Where is the linear portion of the velocity vs substrate concentration?
Up to 1/2 V max
140
What is the definition of Km?
Substrate concentration where velocity equals 1/2 Vmax
141
What type of curve is created with enzyme cooperativity?
Sigmoidal
Rate increase once enzyme has affinity for substrate is greater than linear!
142
Cooperativity is relevant to what kind of enzymes?
Multi-subunit enzymes
143
What is allosteric regulation?
Binding of small molecules to sites on an enzyme that are distinct from the active site.
144
What are relaxed and tense states of active sites?
Tense states are when the active site has a low affinity for substrate
Relaxed state is when the active site has a high affinity for substrate due to cooperativity
145
What is the main differentiator between allosteric regulation and cooperativity?
Cooperativity deals with all substrates binding to different active sites in multi-subunit enzymes.
Allosteric regulation occurs at sites other than active sites
146
Competitive inhibitors resemble what?
Substrate, but effective competitive inhibitors actually structurally mimic the transition state intermediate
147
How can a substrate outcompete an inhibitor?
Increase the substrate concentration
148
The Km of of a reaction is impacted how by the presence of a competitive inhibitor?
The Km is increased. More substrate is need to acquire Vmax of non inhibited enzymatic reaction
149
Is Vmax impacted by competitive inhibitors?
No, still achieve Vmax but with more substrate.
Km is increased
150
What values are and are not impacted by non competitive inhibitors?
Vmax is decreased
1/2 Vmax is decreased
Km is not impacted
151
How is vmax and Km impacted by uncompetitive inhibitors?
Km and Vmax is decreased
152
How is Vmax and Km impacted by mixed inhibitors?
Vmax is decreased and Km is varied.
153
What is another term for non competitive inhibition?
Allosteric inhibition
154
What kind of plot is the line weaver burke plot?
Double reciprocal
Y axis is velocity, lower values on y axis correspond to higher velocity (1/velocity)
X axis is substrate concentration with lower values corresponding to higher substrate concentrations (1/sub conc)
155
What is the definition of the slope on a line weaver Burke plot?
Slope= Km/Vmax
156
What is the definition of the y- intercept on a LWB plot?
Y intercept= 1/Vmax
157
What is the definition of the x intercept on a LWB plot?
X intercept = -1/Km
158
Why does Km decrease when an uncompetitive inhibitor is present?
Since inhibitor bonds to the E-S complex and sequesters enzyme, the inhibitor increases the enzymes affinity for the substrate.
159
How are enzymes that breakdown sugar named?
By the disaccharides they hydrloyze.
160
Glycogen has what kind of glycosidic finds?
Alpha glycosidic bonds
161
What type of glycosidic bonds do cellulose have?
Beta, most mammals lack the ability to hydrolyze beta glycosidic bonds.
162
Is glycolysis inhibited or increased with a the presence of a high concentration of ATP?
Glycolysis is slowed down and inhibited. ATP is an allosteric inhibitor for regulation steps in glycolysis.
Goes against le chatliers principle
163
Where does oxidative phosphorylation occur in prokaryotes?
Cell membrane
164
What transports the NADH from glycolysis in cytoplasm into the inner membrane of the mitochondria?
Glycerol phosphate shuttle
Sends electrons directly to ubiqiunone or complex 2 in ETC
There is a reduction in ATP yield similar to FADH2, only 1.5 ATP made vs 2.5 ATP
165
What reaction is commonly used to drive less favorable reactions? ATP not relevant.
Oxidative decarboxylation
166
Gluconeogenesis can be thought of how?
Glycolysis in reverse with the 3 enzymes catalyzing the 3 irreversible steps replaced.
Start with pyruvate (3carbons)
Convert to OAA (4 carbons)
To phospho-enol pyruvate (3 carbons)
167
List glycolysis/gluconeogenesis regulation strategies
1) energy deficits (high ADP to ATP and NADH to NAD+ ratios) and surpluses ( vice versa)
2) increased concentrations in a pathway serve to decrease the activity of that pathway
3) Fructose 2-6 bus phosphate in glycolysis and gluconeogenesis
Insulin stimulates F,1-6BP formation and activates PFK and stimulates glycolysis
Glucagon triggers breakdown of F,1-6 BP and inhibits PFK and activates F1-6 BPase thereby stimulating glucose biosynthesis
168
List regulation strategies for the Citric Acid Cycle
Cellular energy needs
Pathway intermediate concentrations
NOT hormonal regulated
169
Is glycolysis and gluconeogenesis hormonally regulated?
Yes
| Insulin stimulates glycolysis and glucagon stimulates gluconeogenesis
170
Where does glycogenesis and glycogenolysis occur?
Liver and skeletal muscle
171
Phosphorylated glucose must have what occur for glucose to enter the blood stream?
Be de-phosphorylated
Skeletal muscle keeps the phosphorus group to prevent the glucose from leaving the sketch muscle
172
How is glycogenesis regulated?
Hormonally
by insulin, which stimulates glycogenesis
Glucagon stimulates glycogenolysis
173
What are the 2 main intermediates formed in the pentose phosphate pathway?
Ribose-5-Phosphate. Used in nucleotide synthesis
NADPH is formed- used as reducing species in fatty acid biosynthesis -anabolic pathway
174
What are 2 roles of NADPH?
Used in fatty acid biosynthesis-acts as a reducing species
Used to neutralize reactive oxygen species
175
Pathways that regulate blood glucose levels are regulated how?
Hormonally
Via Cellular energy needs/amount of redox species available
Pathway Intermediate concentrations
176
Why are fats more efficient energy storage molecules than carbs?
1) Packing of fats within the cell
| 2) Are more reduced and thus release more energy via reduced carrier molecules.
177
Unsaturated fatty acids in di-acyl glycerol phosphates (phospholipids) impacts the cell membrane how?
Increases the fluidity of the cell membrane.
178
What are the three modulators that increase cell membrane fluidity?
Increasing the degree of unsaturated fatty acids
Shorter fatty acid tail length
Cholesterol levels
179
All steroids have the structure of?
Tetracyclic ring structure based on cholesterol.
180
Terpenes have the formula of?
(C5H8)n
181
Steroid hormones bind where?
Steroid receptors are found within the cell since their hydrophobicity facilitates diffusion throughout the lipid bilateral
182
What is the significant sphingolipid in humans?
Sphingomyelin found in the myelin sheath of neurons.
183
What are the main fat/lipid structures to know?
Fatty acids-saturated and unsaturated
Triglycerides- fat
Phospholipids- usually have another polar group attached to the phosphate
Cholesterol- has the tetracycline ring structure
Steroids- has the tetracyclic ring structure
Sphingomyelin- component of the myelin sheath
Waxes- fatty acids that are esterified to long chain alcohols. Form protective barriers
Fat soluble vitamins
A, K, D, E
Prostaglandins
Derived from 20 carbon fatty acids and have a 5 member ring structure within
184
Where does fatty acid biosynthesis occur?
Cytoplasm
185
What enzyme cleaves fatty acids from triglycerides?
Lipase
186
What is the priming reaction for fatty acid oxidation?
How many ATP’s are used in this investment stage?
Fatty acid is converted to adenylated fatty acid followed by conversion to fatty acetyl CoA
2 ATP’s used to prime fatty acid so it enter mitochondrial outer membrane
187
What are the reactants, products and steps for fatty acid beta oxidation?
Fatty acid is primed and converted to fatty acetyl CoA
FA-CoA undergoes elimination reaction between alpha and beta carbon to form a trans double bond
FA-CoA double bond undergoes addition reaction with water to form a beta alcohol
Beta alcohol is oxidized to beta ketone
Carbon carbon bond is cleaved between the alpha and beta carbons to form acetyl CoA and shorter chain Fatty acetyl-CoA
Note: once fatty acid carbon chain is cleaved to 4 carbon chain, it is cleaved into 2 acetylCoA’s
188
How many NADH and FADH2 are made with each round of fatty acid oxidation
Each round generated 1 NADH and 1 FADH2
Each acetyl CoA enters the keens cycle and generates 3NADH and 1 FADH2
189
What are the reactants and products of ketogenesis?
2 Acetyl CoA’s over 4 steps are converted to acetoacetate
Acetoacetate is converted to acetone and CO2 or beta hydroxy butyrate
Ketone bodies are able to pass through the blood brain barrier
Ketone bodies are converted back to Acetyl CoA once they reach target organ and enter the Krebs cycle
190
What reducing specie is used in fatty acid biosynthesis?
2 NADPH’s are oxidized to 2 NADP+’s
Oxidizes reducing species formed in the pentose phosphate pathway
191
How does insulin impact glycolysis and glycogenesis?
Insulin stimulates the glycolysis pathway and glycogenesis
192
What are the three reasons why phosphate anhydride bonds store so much free energy?
1) the negative charges of the phosphate groups at biological pH repel each other
2) orthophosphate has more resonance structures than linked phosphates
3) ortho phosphate has more favorable interactions will water than linked phosphates
193
What are the two common forms of inorganic orthophosphate in biological systems?
Hydrogen phosphate and dihydrogen phosphate
PKAs are 2.1, 7.2 and 12.7 of orthophosphate
194
What energy currency molecule is used in glycogenesis?
UTP is used for this specific anabolic pathway
195
Will individual DNA base pairs H bond with each other in water?
No, the double helix structure of DNA facilitated proper orientation of the base pairs in 3D space to allow for H bonding with each other.
196
What portion of a nucleotide constitutes the backbone in a polymer of nucleus acids?
sugar phosphate backbone
197
The binding specificity of enzymes to DNA is derived from interactions with the sugar phosphate backbone or with the purine /pyrimidine based?
Bases because they are the only variable parts of DNA and RNA
198
Name the bases used in DNA and RNA
DNA- A, T, C and G
RNA- A, U, C, and G
199
Poly peptide and protein residues are listed how?
from the N terminus to the Carboxy terminus
200
Nucleotide sequences are listed how?
From the 5’ carbon end to the 3’ carbon end
201
What immediately occurs to pyrophosphate once it is in solution?
Hydrolyzes to 2 inorganic orthophosphate. This along with initial cleavage of ATP drives reactions forward
202
Beta pleated sheets structure depends on H bonds between peptide chains in what orientation?
Antiparallel, when it is one chain looping to H bonding with itself.
203
State chargoffs rule
[A] = [T]
[C] = [G]
[A]+[G]=[T]+[C]
204
What does the term hybridization mean?
The annealing of two complementary strands of DNA
205
A G-C rich nucleotide sequence would have a higher or lower Tm than an A-T rich sequence?
Higher because G-C base pairs form 3 H bonds in dsDNA
206
What interactions stabilize dsDNA double helix?
Van der waals forces and hydrophilic interactions. Once the bases H bond, the dipoles are tied up leaving little polarity left in the structure.
207
What part of the DNA double helix is oriented toward the water and what is oriented towards the interior of the helix?
Sugar phosphate backbone is oriented towards the water and the bases are oriented towards the interior.
208
List the differences in genome characteristics btw Eukaryotes, prokaryotes and viruses.
Eukaryotes- linear DNA, 43 chromosomes, 23 donated from each parent. Largest Mw of all 3.
Prokaryotes- single circular DNA chromosome
Viruses-linear or circular DNA or RNA
209
What are the proteins used to package DNA? What Ana’s are abundant in these proteins?
Histone proteins
N and K, basic r groups are used to attract to the acidic sugar phosphate backbone.
Note at physiological pH the sugar phosphate backbone is deprotonated (have a net negative charge) and the aa side chains are protonated and have a positive charge.
210
Fully packed DNA is called?
Chromatin
211
dsDNA helix wrapped around an octet of histone proteins is called?
A nucleosome
212
The more compacted/denser regions of chromatin is called?
When stained these regions are darker or lighter?
Heterochromatin
Darker
213
The less compacted/less dense parts of chromatin are called?
These regions are darker or lighter when stained?
Euchromatin
Lighter
214
List out flow of DNA structure from deoxy ribose sugar to fully packed chromosome
```
Deoxy ribose sugar
+ base
Nucleoside
+ triphosphate
Nucleotide
+ polymerization with loss of pyrophosphate
Oligionucleotide
+ more polymerization
Single stranded poly nucleotide
+ additional ssDNA and H bonding
dsDNA
+ coiling
dsDNA helix
+ histone protein octet
Nucleosome
+ more packing
Chromatin
```
215
Which part of chromatin has increased gene activity?
Euchromatin because it is less packed and easier for transcription and replication machinery to access DNA
216
Heterochromatin is largely made up of what?
Large sections of repetitive DNA
217
Define centromeres and kinetochores
Centromeres- region of chromosomes where the mitotic spindle fibers attach during mitosis. Made of heterochromatin.
Kinetochores- act mitotic spindles attach to the centromere via these multi protein complexes that act as anchor sites
218
Telomeres are made up of what?
Both ssDNA and dsDNA. Composed of repeat sequences 6-8 bp’s long that are guanine rich.
219
What are the function of telomeres?
Function to prevent chromosome degradation and prevent fusion with neighboring chromosomes.
220
Do prokaryotes have telomeres?
No, since they have circular chromosome they have no chromosome ends.
221
What are the differences btw RNA and DNA?
1) there is a 2’ hydroxyl group on the ribose sugar
2) RNA is single stranded
3) RNA uses the base uracil instead of thymine
222
What is the only coding type of RNA?
mRNA
223
What is the premature version of mRNA called?
heterogenous nuclear RNA hnRNA
224
Do prokaryotes have mRNA?
No backside they do not process their Primary transcripts, thus they only have hnRNA
225
What are the two major noncoding types of RNA?
What are their functions?
tRNA- transfer RNA is used in translation, carries an amino acid from the cytoplasm to the ribosome
rRNA- ribosomal RNA is the major component of ribosomes. Has limited catalytic function.
226
What are catalytic RNA’s called?
Ribozyme
227
What is the composition of a ribosome?
It is made of of rRNA and proteins
228
Acetylcholine is what type of neurotransmitter?
It will depolarize or hyperpolarize a post synaptic membrane?
Excitatory
Depolarize
229
GABA dopamine and norepinephrine are examples of what type of neurotransmitter?
Will they depolarize or hyperpolarize a post synaptic membrane?
Inhibitory
Hyperpolarize- make more negative
230
Can presynaptic neurons change the type of neurotransmitter they release?
No
231
What is the definition of reciprocal inhibition?
Simultaneous inhibition/relaxation of one muscle with the excitation/stimulation of another muscle.
232
The vagus nerve is what type of nerve?
What are the target organs of the vagus nerve?
Cranial nerve
Heart and GI tract
Lower heart rate and stimulate digestion
233
List the types of sensory receptors
```
Mechanoreceptors
Thermoreceptors
Nociceptors- pain receptor
Chemoreceptors
Electromagnetic receptor
```
234
What is the difference between exteroceptors and interoceptors?
Intwroceptors recieve sensory stimuli from inside the soma whereas exteroceptors receive sensory information from outside the soma.
235
What is the definition of a hormone?
A chemical released into the bloodstream by an endocrine gland which has its effects upon a distant target which has the appropriate receptor.
236
What is the characteristic that differentiates between an endocrine gland and an exocrine gland?
Endocrine glands are ductless. They secrete their products into the bloodstream.
Exocrine glands secrete their products to the external environment via gastrointestinal lumen or the external world.
237
Tissue specificity of hormone action is determined by?
Whether the cells of a tissue have the appropriate receptor
238
What are examples of hydrophilic hormones?
Where do they bind?
Peptides and amino acid derivatives
Receptors are located on the cell surface
239
What are examples of hydrophobic hormones?
Where are hydrophobic hormone receptors located?
Steroid hormones
Receptors are located inside the cell
240
Hydrophilic Hormones
Where are they made?
Regulation of release?
Transport in bloodstream?
Specificity
Mechanism of effect
Timing of effect
Rough ER
Stored until released
Free
Target cell surface receptors
Secondary messenger cascade- augment enzyme activity
Rapid, short lived
241
Hydrophobic Hormones
Where are they made?
Regulation of release?
Transport in bloodstream?
Specificity
Mechanism of effect
Timing of effect
Smooth ER
Synthesized only when needed and then immediately released
Stuck to protein carrier
Cytoplasmic receptors
Change the amount and type of enzymes- alter gene expression
Slow- long lasting
242
What is a tropic hormone?
They are hormones that regulate other hormones, not physiological endpoints.
Are also called meta-regulators
243
What are releasing and inhibiting factors(hormones)?
These are hormones released by the hypothalamus that regulate tropic hormones.
244
Another name for factor is?
Hormone
245
Hypophysis is another name for what gland?
Pituitary gland
246
What is the name of the miniature circulatory system used by the hypothalamus to deliver releasing and inhibitory factors?
The hypothalamus-pituitary portal system
247
Adenohypophysis is what?
How is it controlled?
Anterior pituitary gland
It is controlled by the hypothalamus via releasing and inhibiting factors
248
Neurohypophysis is what?
What controls it?
Posterior pituitary gland
Hypothalamic neurons
249
Which is a hormone and which is a neurotransmitter?
Epinephrine is a hormone secreted by the adrenal gland
Norepinephrine is a neurotransmitter
250
Thyroid hormone is what kind of hormone?
Modified amino acid that acts like a steroid
251
What are the 7 major endocrine glands?
Hypothalamus
Pituitary gland
Thyroid gland
Thymus
Adrenal glands
Pancreas
Tested/ovaries
252
What are intergenic regions on chromosomes?
Non coding DNA
Composed of tandem repeats and transposons
253
What are 4 genomic variations?
Single nucleotide polymorphisms- single nucleotide change
Copy number variations- large sections of repeats or deletions
Transposons- mobile genetic elements that jump around the genome
Tandem repeats- repeated sequences
254
What are the two immediate gene products?
Non coding RNA and mRNA
255
Stop codons are also called what?
How many stop codons are there?
Nonsense codons
3
Start with UA
256
How many nucleotides are actually necessary to code for an amino acid in a codon?
Only the first two
257
What is the origin of replication?
The point where DNA replication is initiated.
258
What are important DNA replication rules?
Polymerization occurs in the 5’ to 3’ direction. This means the template strand is read from 3’ to 5’.
DNA polymerase requires a RNA primer. It can only add to an existing nucleotide chain.
DNA requires a template strand/parent strand
Leading strand polymerization is continuous
Lagging strand is dis-continuous-form Okazaki fragments
259
What are the three major enzymes involved in DNA replication?
DNA polymerase (DNA pol III, DNA pol I)
Helicase- unwinds DNA at origin of replication
Topoisomerase - cut DNA strands to unwrap the helix and release tension.
260
All amino acids have what configuration?
L configuration
261
What are the pKas for the carboxylate and amine groups of all amino acids at physiological pH?
Carboxylate pKa is 2.00
Amine pKa is approx. 10.00
262
What are the pKas of the side chains of the charged polar amino acids?
Asp- pKa 4.00
Glu- pKa 4.00
His- pKa 6.00
Lys- pKa 11-12 above amine pKa
Arg- pKa 11-12 above amine pKa
Note that the carboxylate pKa’s are 2.00 and the amino pKa’s are 9- 10
263
What are the letter code abbreviations for
Arginine
Asparagine
Arginine- R charged polar
| Asparagine- N polar
264
Fatty acids are transported in the bloodstream via what protein?
Albumin
265
What must occur to a fatty acid before it can enter the mitochondria to undergo fatty acid oxidation?
It must be primed ( utilizes 2 equivalents of ATP/cleaves two high energy phosphate bonds) and converted into a fatty acid-CoA
266
What is the equation to determine the number of rounds of fatty acid beta oxidation based on the carbon length of the fatty acid?
```
# of rounds of oxidation= (carbon tail length/2)-1
B/c once tail is 4 carbon's long it cleaves in half to make 2 acetyl-CoA's
```
267
Fatty acid biosynthesis occurs where?
Fatty acid catabolism occurs where?
In the cytoplasm
In the mitochondria
268
Are reduced or oxidized species formed during biosynthesis reactions?
Oxidized species are formed
269
What are the starting and ending components of fatty acid biosynthesis?
How many NADP+'s and mol of CO2 are formed?
Acetyl CoA and multiple units of Malonyl CoA (3 carbon chain) converted into C16 fatty acid.
Acetyl CoA is activated via conversion to Malonyl CoA via ATP (1 equivalent) driven carboxylation (addition of CO2).
Each addition of Malonyl CoA to growing fatty acid chain via ACP portion of Fatty Acid Synthase oxidizes 2 NADPH's to 2 NADP+'s (14 NADP+'s produced per 1 C16 fatty acid).
Note* 1 CO2 is used to make each Malonyl CoA, and 1 CO2 is lost with each condensation of Malonyl CoA to growing fatty acid chain at active site.
270
What redox species is used in fatty acid biosynthesis?
NADPH is oxidized to NADP+
