question

The most abundant molecule in the human body is...

answer

Water

question

What are the four most abundant elements in a human body?

answer

Carbon, Nitrogen, Oxygen, Hydrogen

question

Which three cellular components are present in both prokaryotes and eukaryotes? A. ribosomes, chloroplasts, mitochondria B. nucleus, ribosomes, RNA C. RNA, DNA, ribosomes D. endoplasmic reticulum, DNA, RNA E. mitochondria, DNA, RNA

answer

C. RNA, DNA, ribosomes

question

The bulk of aerobic metabolism in eukaryotic cells takes place in the...

answer

Mitochondria

question

Which cellular compartment or organelle is involved in the synthesis of proteins and lipids?

answer

Endoplasmic Reticulum

question

True or False? Carbon, nitrogen, oxygen, hydrogen and calcium are the five most prevalent elements found in the human body.

answer

True

question

Condensation Reaction

answer

A chemical reaction in which two or more molecules combine to produce water and another simple molecule

question

Hydrolysis Reaction

answer

A chemical reaction that breaks apart a larger molecule by adding a molecule of water

question

Brønsted-Lowry Acid

answer

Proton donor

question

Brønsted-Lowry Base

answer

Proton acceptor

question

Hydrophobic Effect

answer

the observed tendency of nonpolar substances to aggregate in aqueous solution and exclude water molecules; occurs because interactions between the hydrophobic molecules allow water molecules to bond more freely, increasing the entropy of the system and decreasing the surface area of the non polar molecules

question

Amphiphilic / Amphipathic

answer

Of or relating to a molecule having a polar, water-soluble group attached to a nonpolar, water-insoluble hydrocarbon chain.

question

The angle of H2O is...

answer

104.5º

question

Interactions Between Permanent Dipoles

answer

interspecific interactions

question

Dipole-Induced Dipole Interactions

answer

dipole moment of polar molecule and polarizability of non-polar molecule

question

London Dispersion Forces

answer

Occur between two instantaneous dipoles; the weakest dipole-dipole force (vs. hydrogen bonds which are the strongest dipole-dipole forces).

question

Dialysis

answer

a procedure to remove waste products from the blood of patients whose kidneys no longer function; blood taken out of the body and urea and creatinine are removed from the blood by diffusion

question

Buffer

answer

A solution that minimizes changes in pH when extraneous acids or bases are added to the solution; pH and pka must be within 1 of each other to be effective

question

Good's Buffers

answer

1. pka from 6-8 2. Soluble in water 3. Membrane impermeability 4. Minimal salt effect (won't interact with other ions) 5. Minimal effect from temp or concentration 6. Well defined or non existent mineral cations 7. Biochemically inert (won't break down) 8. Chemical stability 9. Optical absorbance (? ; 230 nm) 10. Ease of preparation

question

The lower the pka, the _____ (stronger/weaker) the acid

answer

The lower the pka, the stronger the acid

question

The lower the pka, the ________ (more/less) H+ is dissociated

answer

The lower the pka, the MORE H+ is dissociated

question

As pka increases, molecules tend to ____ (lose / gain) acidic hydrogen ions

answer

As pka increases, molecules tend to lose acidic hydrogen ions

question

Metabolic Acidosis

answer

Characterized by a DECREASE in HCO?? level in the serum, leading to an increase in H? concentration and a decrease in pH (below 7.35), , and hyperventilation and a resulting drop in CO2 levels.

question

Metabolic Alkalosis

answer

Characterized by an INCREASE in the HCO?? levels in the serum, leading to a decrease in the H? concentration and an increase in the pH (increase above 7.45), and hypoventilation (too little breathing) and a resulting accumulation of CO2.

question

Respiratory Acidosis

answer

Characterized by excessive RETENTION of CO2 due to hypoventilation; therefore, an increased HCO?? concentration produces an increase in H+ ions and a decrease in the pH (decreases below 7.35).

question

Respiratory Alkalosis

answer

Characterized by a decrease in HCO?? level in the serum, leading to an increase in H? concentration and an increase in pH (above 7.35), , and hyperventilation and a resulting drop in CO2 levels.

question

A red blood cell has an internal salt concentration of ~150mM. The cell is placed in a beaker of 500mM salt. Assuming that the cell membrane is permeable to water but not to ions, water will move from the _____ (lower / higher) field with incorrect answer salt concentration to the _________ (lower / higher) field with incorrect answer salt concentration. If the membrane were permeable to ions, the solutes would diffuse _____ (into / out of) field with correct answer the cell

answer

A red blood cell has an internal salt concentration of ~150mM. The cell is placed in a beaker of 500mM salt. Assuming that the cell membrane is permeable to water but not to ions, water will move from the HIGHER field with incorrect answer salt concentration to the LOWER field with incorrect answer salt concentration. If the membrane were permeable to ions, the solutes would diffuse INTO field with correct answer the cell

question

Which of the following correctly lists bonding interactions in terms of their increasing strength: A) Hydrogen bonds ; ionic interactions ; covalent interactions ; Van der Waals interactions B) Covalent bonds ; hydrogen bonds ; ionic interactions ; Van der Waals interactions C) Van der Waals interactions ; hydrogen bonding ; ionic interactions ; covalent bonds D) Van der Waals interactions ; ionic interactions ; hydrogen bonding ; covalent bonds

answer

C) Van der Waals interactions ; hydrogen bonding ; ionic interactions ; covalent bonds

question

Which of the following statements about water is FALSE? A) Substances with polar functional groups are generally soluble in water. B) The hydrophobic effect is driven largely by the entropy of the non-polar substance. C) Water will act as a hydrogen bond acceptor with hydroxyl groups. D) Water carries a dipole because of the geometry of the two oxygen-hydrogen bonds. E) A network of electrostatic interactions exists between the molecules in water.

answer

B) The hydrophobic effect is driven largely by the entropy of the non-polar substance.

question

The insolubility of nonpolar molecules in water is due to the large _______, which is the result of water molecules forming an ordered network surrounding nonpolar molecules.

answer

Negative entropy

question

Osmotic pressure is a function of A) humidity B) solute size C) solute concentration D) van der Waals forces E) solute vapor pressure

answer

C) solute concentration

question

The pH of coffee is 5.6. The pH of grapefruit juice is 2.6. This means that the proton concentration in coffee is A) 3000 times higher than in grapefruit juice B) 3000 times lower than in grapefruit juice C) a thousand times higher than in grapefruit juice D) a thousand times lower than in grapefruit juice E) 3 times the proton concentration of grapefruit juice

answer

D) a thousand times lower than in grapefruit juice.

question

Open System

answer

A system in which both energy and matter are exchanged with the surroundings.

question

Closed System

answer

A system in which energy, but not matter, is exchanged with its surroundings.

question

Isolated System

answer

A system that exchanges neither matter nor energy with its surroundings.

question

Living organisms are _____ systems. Why?

answer

Open systems because they take nutrients, release waste, and generate work and heat

question

Avogadro's Number

answer

6.02 x 10^23

question

First Law of Thermodynamics

answer

Energy can be transferred and transformed, but it cannot be created or destroyed.

question

q = heat absorbed ____ system ____ surroundings

answer

q = heat absorbed BY system FROM surroundings

question

w = work done ____ system ____ surroundings

answer

w = work dome ON system BY surroundings

question

Explain what happens to water as it freezes

answer

As water cools towards 4ºC, it actually becomes more dense. Then as it reaches 0ºC, its density decreases as its structure opens with freezing. This allows the frozen water / ice to float in water.

question

Amino Acid G

answer

Glycine

question

Amino Acid A

answer

Alanine

question

Amino Acid V

answer

Valine

question

Amino Acid L

answer

Leucine

question

Amino Acid I

answer

Isoleucine

question

Amino Acid M

answer

Methionine

question

Amino Acid P

answer

Proline

question

Amino Acid F

answer

Phenylalanine

question

Amino Acid W

answer

Tryptophan

question

Amino Acid S

answer

Serine

question

Amino Acid T

answer

Threonine

question

Amino Acid N

answer

Asparagine

question

Amino Acid Q

answer

Glutamine

question

Amino Acid Y

answer

Tyrosine

question

Amino Acid C

answer

Cysteine

question

Amino Acid K

answer

Lysine

question

Amino Acid R

answer

Arginine

question

Amino Acid H

answer

Histidine

question

Amino Acid D

answer

Aspartic acid

question

Amino Acid E

answer

Glutamic acid

question

Glycine

answer

G

question

Alanine

answer

A

question

Valine

answer

V

question

Leucine

answer

L

question

Isoleucine

answer

I

question

Methionine

answer

M

question

Proline

answer

P

question

Phenylalanine

answer

F

question

Tryptophan

answer

W

question

Serine

answer

S

question

Threonine

answer

T

question

Asparagine

answer

N

question

Glutamine

answer

Q

question

Tyrosine

answer

Y

question

Cysteine

answer

C

question

Lysine

answer

K

question

Arginine

answer

R

question

Histidine

answer

H

question

Aspartic acid

answer

D

question

Glutamic acid

answer

E

question

Enthalpy (H) Equation

answer

H = U + PV

question

Hess's Law

answer

Regardless of the multiple stages or steps of a reaction, the total enthalpy change for the reaction is the sum of all changes

question

Second Law of Thermodynamics

answer

says that the entropy (disorder) of the universe is increasing. One corollary of the Second Law of thermodynamics is the concept that, in most energy transformations, a significant fraction of energy is lost to the universe as heat.

question

Entropy (S)

answer

a measure of the number of specific ways in which a thermodynamic system can be arranged, commonly known as disorder In a constant energy process (?U = 0) ?S ; 0

question

Gibbs Free Energy

answer

the change in free energy for a process, combines enthalpy, entropy, and temperature Negative - spontaneous = 0 process at equilibrium

question

Conversion from C° to K

answer

K = C° + 273.15

question

?G° Equation

answer

?G° = -RT ln Keq R = 8.314 J/mol•K

question

Concentration of water according to biochemists

answer

55.5M

question

Zwitterions

answer

molecules with both a positive and negative charge that cancel each other out

question

When pH ; pka the molecule is...

answer

PROTINATED

question

When pH ; pka the molecule is...

answer

UNPROTINATED

question

Isoelectric Point

answer

When the molecule is electrically neutral, pI=pH

question

Electrophoresis

answer

The movement of suspended particles through a fluid or gel under the action of an electromotive force applied to electrodes in contact with the suspension.

question

Chirality

answer

If an objects mirror image cannot be superimposed on the original object; lacks internal plane of symmetry

question

Enantiomers

answer

Non-superimposable mirror image

question

Amino acid residues of all proteins have the __ configuration

answer

L configuration

question

Essential amino acids

answer

Amino acids that are needed, but cannot be made by the body; they must be eaten in foods Phe, Val, Thr, Trp, Ile, Met, His, Leu, Lys PVT TIM HaLL

question

Primary Structure of Protein

answer

Amino acid sequence of its polypeptide chains

question

For a protein of n residues there are ___ possible sequences

answer

20^n

question

Neutral Drift

answer

Random mutations in time that do not affect function

question

Invariant Residues

answer

Position has to be a particular, amino acid can't be replaced

question

Conservatively Substituted

answer

Position can be occupied by the same type of amino acid

question

Hypervariable

answer

DNA segment that shows a high degree of variability between members of a population; only functions as a placeholder

question

Orthologous Proteins

answer

Proteins from different species that have homologous amino acid sequences (and often a similar function.) They arose from a common ancestral gene during evolution.

question

Gene Duplication

answer

The generation of extra copies of a gene in a genome over evolutionary time. A mechanism by which genomes can acquire new functions.

question

Paralogous Genes

answer

Genes that are found in the same genome as a result of gene duplication but one has gained a new function.

question

A phylogenetic tree depicts ___________ of proteins. A) folding patterns B) hypervariable residues C) invariable residues D) evolutionary relationships E) gene sequences

answer

D) evolutionary relationships

question

A protein that has had few changes in its amino acid sequence over evolutionary history is labeled A) a fibrinopeptide B) evolutionarily conserved C) random D) a product of pseudogenes E) phylogenetic

answer

B) evolutionarily conserved

question

A fast way for nature to generate new proteins is: A) generation of pseudogenes. B) mutation by neutral drift. C) shuffling protein domains or motifs. D) hypervariable positions. E) liberal substitution.

answer

C) shuffling protein domains or motifs.

question

Proteins are often constructed from multiple segments of 40-200 amino acid residues, commonly called A) pseudogenes B) hypervariable residues C) protolytic fragments D) domains E) subunits

answer

D) domains

question

The amino acid sequence of which type of protein is likely to have changed the least during evolution? A) A protein that makes no important interactions with other proteins B) A protein fragment with no known function C) A protein that has extensive interactions with other proteins and with DNA D) A protein that has some interactions with other proteins

answer

C) A protein that has extensive interactions with other proteins and with DNA

question

The _____ structure of a protein is the amino acid sequence of its polypeptide chain, or chains if the protein consists of more than one polypeptide.

answer

Primary

question

True or False. Only a tiny fraction of all possible proteins exist (i.e. of all combinations of protein sequence possible, evolution has produced only a tiny fraction of the theoretical possibilities).

answer

True

question

True or False. In an evolutionary time frame, the rate at which mutations are accepted into a protein depends upon the function of the protein.

answer

True

question

Which one of the following statements about peptide bonds is FALSE. Peptide bonds are: A) rigid and planar, with partial double-bond character B) involved in forming the primary structure of proteins C) charged D) amides E) covalent

answer

C) charged

question

Which level of protein structure is defined as "the hydrogen bonded arrangement of the polypeptide backbone"? A) Primary B) Secondary C) Tertiary D) Quaternary

answer

B) Secondary

question

A rigid, planar structure between at least two amino acids consisting of about 40% double bond character is characteristic of a _______________.

answer

Peptide group

question

Which of the following is FALSE with respect to ?-sheets? A) ?-sheets may be parallel or anti-parallel. B) Strands in a ?-sheet are connected by irregular loops. C) ?-sheets are stabilized by non-covalent forces. D) Amino acid side chains protrude from one side of the ?-sheet

answer

D) Amino acid side chains protrude from one side of the ?-sheet

question

Repeating values of ? and ? make up predictable orientations of amino acid with a chain, this predictable orientation forms _________________

answer

Regular secondary structure

question

The strength of Entry field with _________ comes from close packing of glycine residues and the characteristics of hydroxyproline allowing formation of a left-handed helical conformation which combines with two other left-handed structures to form a right-handed triplet helix.

answer

collagen

question

Helix-Entry field with _________ is the phenomenon in which side chains of residues just outside -helices make hydrogen bonds to the backbone groups of the four terminal residues of the helix.

answer

capping

question

Which of the following describes the entire three-dimensional structure of a single polypeptide? A) Tertiary structure B) Secondary structure C) Quaternary structure D) Primary structure

answer

A) Tertiary structure

question

What is the primary driving force in the formation of protein tertiary structure? A) The exclusion of non-polar substances from aqueous solution. B) The formation of van der Waals interactions between neighbouring groups. C) Energy released when additional ion pairs are formed. D) Energy released when additional hydrogen bonds are formed.

answer

A) The exclusion of non-polar substances from aqueous solution.

question

Which of the following statements about quaternary structure is TRUE? A) Quaternary structure requires covalent interactions between polypeptide chains. B) Quaternary structure is defined as the precise, 3-D arrangement of polypeptide backbones in proteins with more than one subunit. C) Quaternary structure exists in monomeric proteins. D) Quaternary structure is stabilized by the same types of noncovalent interactions as tertiary structure

answer

D) Quaternary structure is stabilized by the same types of noncovalent interactions as tertiary structure

question

The overall arrangement of the regular structural elements such as the alpha helix and the ? sheet in the protein are considered the protein's _________

answer

tertiary structure

question

The __________ of an amino acid can be used to predict whether an amino acid side chain folds towards the inside or outside of a globular protein.

answer

hydropathy

question

What is the major factor that "drives" the folding of proteins into their tertiary structure? A) Placement of polar amino acid residues on the surface of the protein. B) Placement of hydrophobic amino acid residues within the interior of the protein. C) Formation of the maximum number of hydrophilic interactions. D) Formation of the maximum number of ionic interactions.

answer

B) Placement of hydrophobic amino acid residues within the interior of the protein.

question

Secondary Structure

answer

The local spatial arrangement of a polypeptide's backbone atoms without regard for its side chain

question

Tertiary Structure

answer

the three-dimensional form of an entire polypeptide, including its side chains

question

Quaternary Structure

answer

the spatial arrangement of protein subunits

question

? (Psi) Angle

answer

angle in polypeptide backbone, torsion angle around the C?-C bond

question

? (Phi) Angle

answer

angle in polypeptide backbone, torsion angle around the C?-N bond

question

Ramachandran Diagram

answer

A steric countour duagram that depicts allowed ranges of the angles phi and psi for amino acid residues in polypeptide cahins. For each residue, its confirmation in the main chain of polypeptide can be completely defined by the psi and phi angles

question

?-helix

answer

A protein secondary structure - a right-handed spiral held in place by hydrogen bonds between adjacent C=O and NH groups The side chains project outward and down which avoids steric hindrance Tightly packed - van der Waals contact

question

?-pleated sheet

answer

An element of secondary structure, marked by peptide chains lying alongside one another, forming rows or strands H-bonding occurs between polypeptide chains Anti-parallel or parallel (slightly less stable) Side chains extend to opposite sides of sheets

question

Globular Proteins

answer

These proteins are small spheres with little to no water inside. They have hydrophobic amino acids in the inside and hydrophilic R groups on the outside Water soluble, characterized by compact and highly folded structure

question

Fibrous Proteins

answer

These form extended sheets or strands, making them tough, durable, and generally insoluble in water; form fibers

question

Keratin

answer

fibrous protein, mechanically durable and relatively unreactive, two alpha helices coiling around each other, heptad repeat Lots of keratin causes curly hair

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