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BIOCHEM- Practice Exam 1

Terms in this set (83)

The first step in cell lysis is called ______________ and this breaks the cell by __________ ___________ __________ ___________.
sonication
high frequency sound waves
What enzymes are used during the first process of cell lysis?
lysozomes
Taking out or removing material inside the cell is called what?
homogenate
_________ is the process of spinning a sample at high speed and creating two separate products. These products are called ________ and ________.
centrifugation
pellet, supernatant
Supernatant contains what type of material? Pellet?
liquid part of centrifugation; most proteins
base and solid part of centrifugation; DNA/RNA/lipids
How does desalting remove salt from the supernatant product?
By placing the supernatant (high conc.) in the semi-pourous-porous dialysis tube, and then placing the tube in a buffer solution (low conc.). The opposite concentrations cause the small salts to diffuse through the pores and leaves the large proteins behind.
Size exclusion chromatography is also called ____________ _____________ ____________ and uses porous beads made of the inert material ____________.
Molecular Size Chromatography
cellulose
What two chemicals are used in Ion Exchange Chromatography? Are they +/- and cation/anion exchanger?
Carboxymethyl (CM) cellulose- (+) anion exchanger
Diethylaminoethyl (DEAE) cellulose- (-) cation exchanger
____________ is the use of a buffer to change the pH of a solution to extract desire protein. The buffer is referred to as an __________.
Elution
eluant or elutant
The y-axis of a chromatogram displays a proteins _________ and the x-axis shows the _________ _________.
intensity; (amount of protein in sample)
retention time; (how long protein remained in column)
Gel Electrophoresis is based on _______ _______ and treats the samples with ____________ _____________ ___________ to give the sample a (-) charge.
protein size
sodium dodecyl sulphate (SDS)
Polyacrylamide Gel Electrophoresis is __________ packed and _______ porous compared to normal Gel Electrophoresis.
tightly
more
What is used to stain proteins in Polyacrylamide Gel Electrophoresis?
commassie blue
What gel is used during Gel Electrophoresis when testing DNA?
agarose
What does ELISA stand for?
Enzyme Linked Imunno Sorbent Assay
Antibodies are _______ proteins and are thus called ______________. What are the 5 types of antibodies?
globular, immunoglobulins
IgA, IgM, IgD, IgE, IgG
A polyclonal cell uses the same type of ________ but a different type of __________ and monoclonal cells use the same __________ but different ______________.
antibodies, B cells
B cell, antibodies
Fusion of a B cell with a _________ cell is done in many labs to create _________ antibodies. The fusion product is known as a __________.
tumor
monoclonal
hybridoma
The Blotting technique first uses ________ gel to adhere sample protein bands to testing paper. The proteins are then blotted onto a __________ ___________ paper.
agrose
nitrous cellulose
What are the four types of Blotting?
Northern = RNA
Southern = DNA
Eastern = carbohydrates
Western = proteins
ELISA uses a _________________ well plate and is largely used to test ________ _________ _________.
polystyrene
sexually transmitted infections
__________ ELISA first places the antigen in the well plate followed by the antibody. Oppositely, ___________ ELISA places the antibody first and then the antigen.
indirect
sandwich
___________ is added to the __________ and provides a _________ ________ in ELISA tests to indicate infection.
substrate
enzyme
color change
Which ELISA test is used to test against HIV?
indirect
The energy spectrum of gamma rays is used to detect what?
decaying radionuclides
Infrared Spectroscopy detects _______ ________ present in protein and _________ __________ detects the molecular structure of a protein.
functional groups
X-Ray Crystallography
What does UV Spectroscopy detect?
if the protein has a conjugated electron system
_____________ ___________ identifies the size and formula of a protein. The protein sample is first __________ by one of 2 techniques. These techniques are ______________ and _____________.
Mass Spectroscopy
fragmented
MALDI
Electron Spray Ionization (ESI)
A hemoglobin molecule is made up of _________ and 2 ____________ and 2 __________ subunits. Therefore, hemoglobin is referred to as a "__________ of a ________ ".
proteins
alpha
beta
dimer of a dimer
What are the important structures of a heme group?
4 pyrrole rings "tetrapyrrole"
proximal/distal histadine
1 central Fe2+ atom
*methine bridges
When bound to oxygen, iron (raises / lowers) 0.4 A' where it then is (below / level with) the heme group.
raises
level with
If the oxygen - iron bond breaks asymmetrically, ______ _________ are created and can cause damage to ______ __________
oxygen radicals
DNA/RNA function
What is another name for oxygen radicals? What is used to combat these radicals?
superoxide anions
superoxide dismutase (SOD)
What form of iron binds oxygen and what is its chemical name?
Fe2+ Ferrous cation
When there is not enough oxygen supply, ______________ is used for back up. This molecule loses its affinity for oxygen when the concentration is _____.
myoglobin
zero
What is the function of proximal histidine and what is it bonded to? Distal histidine functions to ________ oxygen.
Proximal - holds Fe in middle of heme group
stabilize oxygen
Referring to the oxygen dissociation (affinity) curve, myoglobin represents a _____________ curve and hemoglobin represents a ______________ curve.
hyperbole
sigmoidal
When hemoglobin has not yet bound oxygen, it is in what state? What happens when it does bind oxygen? Name this model.
When unbound hemoglobin spontaneously goes between R and T states. When bound it is then stuck in the state it was previously in.
Concerted model
Bounded oxygen molecules helping other oxygen models bind to adjacent subunits is called the __________ model. This causes change in the molecule which increases what?
Sequential
chances of subsequent binding
Other things bind to hemoglobin other than oxygen and are called ________ _________. This includes _____________________, ______________ and _______.
allosteric effectors
2,3-Bisphosphoglycerate
carbon dioxide
Hydrogen ions
RBC contain _______________ ____________ which produces 2,3-biosphosphoglycerate from 1,3-BPG.
bisphosphoglycerate mutase
What is the difference between "bis", "di" and "bi"?
bis = 2 phosphate groups attached to 2 different carbons on same side

di = 2 phosphates attached on same side, one attached to alpha carbon and other attached to adjacent phosphate

bi = 2 phosphates attached to alpha carbon but on opposite sides
Carbon dioxide is converted to __________ via _______. Some carbon dioxide binds to _________ making affinity for oxygen _______.
carbonic acid
carbonic anhydrase
hemoglobin
lowers
H+ ions _______ pH and _______ hemoglobins affinity for oxygen. When pH is ________, chemical signals tell the body that ________ levels are high. This is know as ________ _________.
lower
lowers
low
carbon dioxide
Bohr's effect
When 2,3-BPG binds to hemoglobin at specific a.a. residues, it induces _____ _______ triggering the release of oxygen. 2,3-BPG is referred to as a ____________ __________.
shape change
metabolic biproduct
Explain the path hemoglobin takes to bring oxygen to cells in need.
Breathe in air - deoxyhemoglobin in lungs receive and binds oxygen - now oxyhemoglobin travels to metabolizing cells who are producing 2,3-BPG - release oxygen to cells - deoxyhemoglobin travels back to lungs to bind more oxygen - enzyme (bisphosphoglycerate mutase) removes 2,3-BPG from cells.
What causes the pH in a cell to drop besides H+ ions?
carbonic acid
RBC are colored red because of their ________ _______. Because of the ____________ ____________, hemoglobin binds RBC and creates a shape change into a __________ shape.
heme group
hydrophobicity patch
disk
When hbb is mutated into ______, ______ is replaced by _______ in the 6th position in beta chains. This swapping of oppositely charged a.a. creates a ___________ ___________. Why?
hbs
Glu
Val
Hydrophobicity Patch
Glu is a polar/hydrophilic molecule and is replaced by the non-polar/hydrophobic molecule Val. Val interacts with other hydrophobic a.a. creating the hydrophobicity patch.
When both allele copies of the beta chains are mutated, this causes what? What happens when only one is mutated?
Sickle Cell Anemia
become a "carrier"
___________ are immune to Malaria but because of this, creates the phenomena ________ __________ _________. How?
carriers
external selection pressure
Because only carriers are immune to the disease but are still able to pass to offspring, this leaves the chances of two parents both being carriers and passing both copies to offspring. Now can have Sickle Cell Anemia.
The parasite ___________ _________ or __________ __________ causes Malaria and is spread through __________.
plasmodium falciparus
plasmodium vivax
mosquitos
When the hba chain is not made in enough quantity or not at all, individual can get ____________ ___________, also known as ____ _________ _______.
Alpha Thallesemia
Alpha Thallasemia Minor
What are two other proteins that bind oxygen other than hemoglobin, myoglobin and fetal hemoglobin?
hemerythrin
hemocyanin
Cooley's Anemia is another name for what condition? Name another name for this condition.
Beta Thallesemia/ Thallesemia minor
*Beta - zero Thallesemia
Fetal hemoglobin contains 2 _________ subunits and 2 _________ subunits. The importance of the __________ subunits is due to its __________ affinity for oxygen.
alpha
gamma
gamma
high
RNA catalyzes reactions in the form of ___________.
ribozymes
Enzymes are ________ __________. These enzymes contain high ____________, also known as enzyme commission. What are the 6 categories based on this?
biological catalysts
specificity
1. ligases
2. isomerases
3. lyases
4. hydrolyses
5. transferases
6. oxidoreductases
____________ are non-functioning enzymes that need assistance from _______. The two together form a __________.
apoenzymes
cofactors
holoenzyme
What are the 3 types of organic cofactors? What are inorganic cofactors labeled as?
1. coenzyme (vitamins)
2. co-substrates; bind loosely
3. prosthetic groups; bind tightly
metals (most divalent)- transition metals
A high affinity for an enzyme has a ________ Km and a low affinity for an enzyme has a ________ Km. What is used to find Km and what does Km show?
low
high
Michaelis-Menten graph
amount of substrate concentration relative to Vmax / 2
Double Reciprocal Graph labels _____/_____ on the y-axis and _____/_____ on the x-axis. What is another name for this graph?
1 / [Vo]
1 / [S]
Lineweaver Burk Plot
What is the name of the model that displays a perfect fit between the substrate and enzymes active site? What model binds substrate to enzyme to induce active site shape change?
lock & key model
induced fit model
___________ _________ can bind non-substrate molecules and do not follow the _________ _______ graph. They often display _______ plots and are key regulators in metabolic pathways.
allosteric enzymes
Michaelis-Menten
sigmoidal
What type of enzymes can bind multiple substrates?
allosteric enzymes
What are the different types of bisubstrate enzyme reactions?
sequential
ping-pong (double displacement)
In __________ sequential reactions, substrates induce shape change on ________ ______ for next substrate to bind. The enzyme that catalyzes this reaction is ____________ ____________.
ordered
active site
lactate dehydrogenase
In a ordered sequential reaction the products are released _____________. The substrates in this reaction are _________, ________ and _________ and the products produced are ________ and ________.
at the same time
pyruvate
NADH
H+
lactate
NAD+
The enzyme used in the random sequential reaction is _______ _________. The substrates of this reaction are ____ and _____ forming the products _____ and _______.
creatine kinase
creatine
ATP
phosphocreatine
ADP
What happens in a ping-pong reaction? Name the substrates, products and enzymes used.
functional groups are swapped between substrates functional groups. enzyme is transiently modified and only one product is released at a time.
aspartate + a-ketoglutarate > oxaloacetate + glutamate
enzyme- aspartateamino transferase
When delta G>0 the reaction is said to be ______, conversely when delta G<0 the reaction is ___________. _________ is favorable.
endergonic
exergonic
exergonic
__________ completely make an enzyme non-functional. The process of this is divided into ___________ and _________ categories.
inhibitors
reversible
irreversible
During ________ inhibition, inhibitor binds to active site causing the _________ to increase. In turn, this _________ the substrates ________ to the enzyme.
competitive
Km
decreases
affinity
What type of inhibition can be overcome by increasing the substrate concentration?
competitive inhibition
Dihydrofolate is used to make nucleic acids and is the substrate for _____________. It's competitive inhibitor is____________ and it is used in ________________. Whats it do?
dihydrofolate reductase
methorexate
chemotherapy
slow the reproduction of cancer cells
_______________ inhibition does not bind to the active site and is said to be substrate dependent. It instead binds to the ________ ________ _________.
uncompetitive
enzyme substrate complex
What type of inhibition results in an increase in Vmax and is displayed by Inositol monosphosphatase inhibited by lithium?
uncompetitive inhibition
__________ inhibition can either bind the _______ _________ or the ______ ________ ______. it (can / cannot) be overcome by increasing the substrate concentration and an example of this is __________ inhibited by __________.
non-competitive
free enzyme
enzyme substrate complex
cannot
dehydrogenase
cyanide
________ inhibition use non-covalent interactions and _____ inhibition use covalent bonding.
reversible
irreversible
What are the 3 types of reversible inhibition?
1. competitive
2. uncompetitive
3. non-competitive
________ _______ ______ and _______/_______ ________ are examples of irreversible inhibition.
active site analogs
suicide/mechanism base
Acetylcholine esterase is inhibited by _____________ __________ and leads to ___________. This is an example of ________ inhibition known as ____ ________ ______.
DIPF (diisopropyl Fluorophosphate
paralysis
irreversible
active site analogs
Individuals are prescribed deprenyl, which acts as a _________, when their serotonin levels are low. This is due to the enzyme ____________ ________. This is an example of the __________ inhibition _____/ ________ ______.
inhibitor
monoamine oxidases (MAO)
irreversible
suicide/ mechanism base
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