240 PRBLMS but an A ain't one
Covalent bond
A chemical bond that involves sharing a pair of electrons between atoms in a molecule
alpha helix
A coiled region constituting one form of the secondary structure of proteins, arising from a specific pattern of hydrogen bonding between atoms of the polypeptide backbone (not the side chains).
Spectrin
A fibrous protein that gives shape to an RBC plasma membrane.
Lectin
A protein that binds a carbohydrate, commonly an oligosaccharide, with very high affinity and specificity, mediating cell-cell interactions.
Cholesterol
A steroid that is an important component of animal cell membranes and that acts as a precursor molecule for the synthesis of other steroids such as hormones.
Prokaryotes vs. Eukaryotes
- Prokaryotes have no nucleus or membrane bound organelles - Eukaryotes have a nucleus and membrane bound organelles - Both can reproduce and respond to the environment
What is the function of the lysosomes?
-break down materials and waste -host defense (destruction of bacteria by white blood cells)
What is the volume of E. coli?
1 micrometer^3
What is the order of magnitude mass of E. coli?
1 pg
At neutral pH, the concentration of H+ ions in pure water is ______.
1*10^-7
Nucleosomes are formed when DNA wraps ____ times around the histone octamer in a _____.
1.7, left-handed coil
T/F: If a hormone is spread through the body through endocrine signaling, all cells have to respond to it.
F
T/F: Stratified epithelial cell sheets cover luminal hollow tubular surfaces in the small intestine and columnar epithelium cells cover the blood vessel walls
F
T/F: cells can signal to each other in various ways. A signal that must be relayed to the entire body is most efficiently sent by endothelial cells, which produce hormones are carried through the bloodstream.
F
T/F: lysosomes are believed to have originated from engulfment of bacteria specialized in digestion.
F
True or False, standard action potential's in biochemistry correspond to solutions with [H+] = 1M
False
What are examples of intermediate filaments?
Keratin, neurofilaments, vimentin
Cortex
Meshwork of fibrous proteins that determine the shape of the cell and the mechanical properties of the plasma membrane; attached to the cytosolic surface of the membrane
What is the base unit measuring cells?
Micrometers
Which protein filament is GTP hydrolysis associated with?
Microtubules
What is the function of the Golgi?
Modifies, sorts, and packages proteins and lipids for storage or transport out of the cell
Evolution is a process that can be understood based on the principles of _________.
Mutation and selection
The linear sequence of polypeptide chains are always read ______.
N-terminus to C-terminus
Each electrical impulse stimulates the nerve terminal to release a pulse of an extra cellular signal molecule called a _______.
Neurotransmitter
Adiabatic
No heat transfer: compression/ expansion. Work is done on/ by gas
beta pleated sheet
One form of the secondary structure of proteins in which the polypeptide chain folds back and forth, or where two regions of the chain lie parallel to each other and are held together by hydrogen bonds.
What is the key assumption of Michaelis-Menten kinetics?
The concentration of the enzyme-substrate complex does not change with time. This is called the steady state approximation.
If two genes are next to each other on a chromosome, separated by introns, explain rate at which each can be transcribed.
The two genes can be transcribed at different rates, producing different amounts of RNA within the same cell.
secondary structure of protein
The way in which the chain of amino acids of the polypeptides of a protein is folded; alpha helix and beta pleated sheet
Which of the following statements is true? a. Extracellular signal molecules that are hydrophilic must bind to a cell-surface receptor so as to signal the target cell to change its behavior. b. To function, all extracellular signal molecules must be transported by their receptor across the plasma membrane into the cytosol. c. A cell-surface receptor capable of binding only one type of signal molecule can mediate only one kind of cell response. d. Any foreign substance that binds to a receptor for a normal signal molecule will always induce the same response that is produced by that single molecule on the same cell type.
a. Extracellular signal molecules that are hydrophilic must bind to a cell-surface receptor so as to signal the target cell to change its behavior.
All the statements are true except: a. Gene duplication occurs by equal crossing-over between short repeated sequences on heterogeneous segments of DNA b. DNA duplications give rise to families of related genes within a single sell c. a single-chain globin molecule gave rise to the four chain hemoglobin used by humans and other mammals d. new genes come into existence by gene duplication and mutation accumulation
a. Gene duplication occurs by equal crossing-over between short repeated sequences on heterogeneous segments of DNA
What is the role of the nuclear localization sequence in a nuclear protein? a. It is bound by cytoplasmic proteins that direct the nuclear protein to the nuclear pore. b. It is a hydrophobic sequence that enables the protein to enter the nuclear membranes. c. It aids in protein unfolding so that the protein can thread through nuclear pores. d. It prevents the protein from diffusing out of the nucleus through nuclear pores.
a. It is bound by cytoplasmic proteins that direct the nuclear protein to the nuclear pore.
What is the role of the nuclear localization sequence in a nuclear protein? a. It is bound by cytoplasmic proteins that direct the nuclear protein to the nuclear pore. b. It is a hydrophobic sequence that enables the protein to enter the nuclear membranes. c. It aids in protein unfolding so that the protein can thread through nuclear pores. d. It prevents the proteins from diffusing out of the nucleus through nuclear pores.
a. It is bound by cytoplasmic proteins that direct the nuclear protein to the nuclear pore.
Which of the following descriptions is consistent with the behavior of a cell that lacks a protein required for checkpoint mechanism that operates in G2? a. The cell would be on able to enter M phase. b. The cell would be unable to enter G2. c. The cell would enter M phase under conditions when normal cells would not. d. The cells would pass through M phase more slowly than normal cells.
a. The cell would be on able to enter M phase.
Which of the following statements is TRUE? a. The position of introns in most genes is conserved among vertebrates. b. The more nucleotides there are in an organism's genome, the more genes there will be in its genome. c. Because the fly Drosophila melanogaster and humans diverged from a common ancestor so long ago, any two fly genes will show more similarity to each other then it will to human gene. d. Two closely related organisms are more likely to have a genome of the same size than a more evolutionarily diverged animal.
a. The position of introns in most genes is conserved among vertebrates.
All members of the steroid hormone receptor family are ______. a. are cell surface receptors. b. do not undergo confirmational changes. c. are found only in the cytoplasm. d. interact with cell signal molecules and diffuse through the mitochondrial membrane
a. are cell surface receptors.
Proteins that are fully translated in the cytosol and lack a sorting signal will end up in the ____. a. cytosol b. mitochondria c. interior of the nucleus d. nuclear membrane
a. cytosol
DNA polymerase catalyzes the joining of a nucleotide to the growing DNA strand. What prevents this enzyme from catalyzing the reverse reaction? a. hydrolysis of pyrophosphate (PPi) to inorganic phosphate (Pi) + Pi b. Release of PPi from the nucleotide c. Hybridization of the new strand to the template d. Loss of ATP as an energy source
a. hydrolysis of pyrophosphate (PPi) to inorganic phosphate (Pi) + Pi
Methylation and acetylation are common changes made to histone H3, and the specific combination of these changes is sometimes referred to as the "histone code." Which of the following patterns probably lead to gene silencing? a. lysine 9 methylation b. lysine 4 methylation and lysine 9 acetylation c. lysine 14 methylation d. lysine 9 acetylation and lysine 14 acetylation
a. lysine 9 methylation
Order the three types of protein filaments that make up the cell's cytoskeleton from least to greatest diameter.
actin, intermediate filaments, microtubules
What is the most electronegative atom? a. Oxygen b. F c. Cl d. C
b. F
Which of the following statements about RNA splicing is false? a. Conventional introns are not found in bacterial genes. b. For a gene to function properly, every exon must be removed from the primary transcript in the same fashion on every mRNA molecule produced from the same gene. c. Small RNA molecules in the nucleus perform the splicing reactions necessary for the removal of introns. d. Splicing occurs after the 5' cap has been added to the end of the primary transcript.
b. For a gene to function properly, every exon must be removed from the primary transcript in the same fashion on every mRNA molecule produced from the same gene.
Which of the following is true about the reaction quotient? a. When it is less than K, the reaction proceeds towards the products. b. When it is less than K, the change in Gibbs free energy is negative. c. When it is equal to K, the mass action ratio is unity. d. All of these
d. All of these
In passive transport with no barriers, if the concentration of molecules is high in one area below another area, then ______. a. the molecules will have a net flux to the area of low concentration b. the concentration will tend to be equal on both areas after a long period of time c. the diffusion process can be modeled as a random walk d. All of thses
d. All of theses
The standard state pressure is a. 1 atm b. 760 mm of Mercury c. 101,300 Pascals d. All of these
d. All uh deez
Which of the following are extensive properties? a. Temperature b. Pressure c. Density d. None of the above
d. None of the above
What would be the most obvious outcome of repeated cell cycles consisting of S phase and M phase only? a. The cells would not be able to replicate their DNA. b. The mitotic spindle could not assemble. c. The cells would get larger and larger. d. The cells produced would get smaller and smaller.
d. The cells produced would get smaller and smaller.
After isolating the rough endoplasmic reticulum from the rest of the cytoplasm, you purify the RNAs attached to it. Which of the following proteins do you expect the RNA from the rough endoplasmic reticulum to encode? a. Soluble secreted proteins b. ER membrane proteins c. plasma membrane proteins d. all these answers are correct
d. all of these answers are correct
snRNAs _________. a. are translated into snRNPs b. are important for producing mature mRNA transcripts in bacteria c. are removed by the spliceosome during RNA splicing d. can bind to specific sequences at intron-exon boundaries through the complementary base-pairing
d. can bind to specific sequences at intron-exon boundaries through the complementary base-pairing
You isolate a pathogenic strain of E. coli from a patient and discover that this E. coli strain is resistant to an antibiotic. Common laboratory strains of E. coli are not resistant to the antibiotic, nor any other previously isolated pathogenic E. coli strains. However, such resistance has been observed in other bacteria in the hospital which the patient was treated. This newly discovered antibiotic resistance in E. coli is most likely due to a. a mutation with a gene. b. a mutation within the regulatory DNA of a gene. c. gene-duplication. d. horizontal gene transfer.
d. horizontal gene transfer.
According to current thinking, the minimum requirement for life to originated on earth was the formation of a _____. a. molecule that could provide a template for the production of a complementary molecule b. double-stranded DNA helix c. molecule that could direct protein synthesis d. molecule that can catalyze it own replication
d. molecule that can catalyze it own replication
Active transport requires the input of energy into a system so as to move solutes against their electrochemical and concentration gradients. Which of the following is NOT one of the common ways to perform active transport? a. Na+-coupled b. K+-coupled c. ATP-driven d. light-driven
b. K+-coupled
A basal lamina _____. a. is a thin layer of connective-tissue cells and matrix underlying an epithelium b. is a thin layer of extracellular matrix underlying an epithelium c. is attached to the apical surface of an epithelium d. separates epithelial cells from each other
b. is a thin layer of extracellular matrix underlying an epithelium
Carrier proteins
bind to molecules and change shape to shuttle them across the membrane
Transcription is similar to DNA replication in that ________. a. an RNA transcript is synthesized discontinuously and the pieces are then joined together. b. it uses the same enzyme as that used to synthesize RNA primers during DNA replication. c. the newly synthesized RNA remains paired to the template DNA. d. nucleotide polymerization occurs only in the 5' to 3' direction.
d. nucleotide polymerization occurs only in the 5' to 3' direction.
Which statement about ER is false? a. ER is the site for new synthesis b. steroid hormones synthesized on smooth ER c. ER membrane is continuous with outer nuclear membrane d. proteins to be delivered to the ER are synthesized in smooth ER
d. proteins to be delivered to the ER are synthesized in smooth ER
Proteins that are fully translated in the cytosol do not end up in a. the cytosol b. the mitochondria c. the interior of the nucleus d. transport vesicles
d. transport vesicles
The local mediator nitric oxide stimulates the intracellular enzyme guanylyl cyclase by ________.
diffusing into cells and stimulating the cyclase directly
Genes and genomes can be altered by several different mechanisms such as: a. Gene duplication b. Gene deletion c. exon shuffling d. mutation within a gene e. All of the above
e. All of the above
Amphipathic
having both a hydrophilic region and a hydrophobic region
Increase in water causes folding because of ______ side chains.
hydrophobic
The ribosome is important for catalyzing the formation of peptide bonds. Which of the following statements is true? a. The number of rRNA molecules that make up a ribosome greatly exceeds the number of protein molecules found in the ribosome. b. The large subunit of the ribosome is important for binding to the mRNA. c. The catalytic site for a peptide bond formation is formed primarily from an rRNA. d. Once the large and small subunits of the ribosome assemble, they will not separate from each other until degraded by the proteasome.
c. The catalytic site for a peptide bond formation is formed primarily from an rRNA.
dipole-dipole forces
intermolecular forces that exist between polar molecules. Active only when the molecules are close together. The strengths of intermolecular attractions increase when polarity increases
Which of the following is important in a functional microvilli? a. microtubules b. basal body c. actin d. intermediate filaments
c. actin
The basal body is an organizing center for _____. a. mitotic spindle b. centrosome c. ciliary microtubules d. microvilli
c. ciliary microtubules
Ras is GTP-binding protein that is often defective in cancer cells. A common mutation found in cancer cells causes Ras to behave as though it were bound to GTP all the time, which will cause cells to divide inappropriately. From this description, the normal Ras gene is a/an ______. a. tumor suppressor b. oncogene c. proto-oncogene d. gain-of-function mutation
c. proto-oncogene
Which of the following statements is true? a. Ribosomes are large RNA structures composed solely of rRNA. b. Ribosomes are synthesized entirely in the cytoplasm. c. rRNA contains the catalytic activity that joins amino acids together. d. A ribosome binds only one tRNA during peptide elongation step.
c. rRNA contains the catalytic activity that joins amino acids together.
What is the function of the mitochondria?
cellular respiration
Levels of Cdk activity change during the cell cycle, in part, because ________________.
cyclin activity change during the cycle
Channel proteins
proteins that provide passageways through the membrane for certain hydrophilic (water-soluble) substances such as polar and charged molecules
RNA splicing is carried out by
snRNPs
Saturated fats
solid at room temperature; no double bonds
Lumen
space within a tubular part or organ, such as the space within a blood vessel
primary structure of protein
the amino acid sequence of the polypeptide chain
Anode
the electrode at which oxidation occurs
cathode
the electrode at which reduction occurs
Passive transport
the movement of substances across a cell membrane without the use of energy by the cell
Advection
the transfer of heat or matter by the flow of a fluid, especially horizontally in the atmosphere or the sea.
van der Waals forces
the two weakest intermolecular attractions- dispersion interactions and dipole forces
Metastatic tumors
tumors that grow from infiltrating cells that are carried to the brain by the bloodstream from some other part of the body
The linear sequence of nucleic acid chains are always read ______.
5' to 3'
Somatic cells
Any cells in the body other than reproductive cells
Basal body
Array of microtubules at the base of cilia or flagella act as an organizing center
For both actin and microtubule polymerization, nucleotide hydrolysis is important for __________.
Decreasing the binding strength between subunits on filaments
tertiary structure of protein
Defined by the hydrophilic and hydrophobic interactions between R groups of amino acid chains; large 3D structure
What is the fastest type of transport across the body?
Endocrine
Protein folding is due to what two factors?
Energy and entropy
Active transport
Energy-requiring process that moves material across a cell membrane against a concentration difference
What is the function of the nucleus?
Contains the cell's genetic material.
Paracrine signaling
Rather than entering the bloodstream, the signal molecules diffuse locally through extracellular fluid, remaining in the neighborhood of the cell that secretes them
SARS-CoV-2 research entails the lentivirus with which characteristic?
Spike protein pseudotyped (Spp) lentivirus
Pluripotent stem cells
Stem cells that can become almost all types of tissues and cells in the body.
T/F: Recycling of organelles happens in the lysosome due to degrading enzymes that are present
T
T/F: Regulatory proteins can switch genes on and off by binding to regulatory sequences- mainly in the major groove
T
T/F: The lysosome originated from the government of a bacteria with some type of digestive enzymes
T
T/F: molecules will spontaneously go from high concentration to low concentration.
T
What is the mechanism by which chromatin-remodeling complexes "loosen" the DNA wrapped around the core histones?
They use the energy derived from ATP hydrolysis to change the relative position of the DNA in the core histone octamer.
________ are formed from claudins and occludins.
Tight junctions
Which direction does dynein move?
Towards - end
Which direction does kinesin move?
Towards the + end
Hydrogen bonds
Very weak bonds; occurs when a hydrogen atom in one molecule is attracted to the electrostatic atom in another molecule
Which of the following lipid head groups is not zwitterionic? a. Phosphatidylethanolamine b. Phosphatidylcholine c. Phosphatidylserine d. All of these
c. Phosphatidylserine
What is a paramecium?
a protist with cilia and two types of nuclei
Which cellular organelle has an inner and outer membrane? a. ER b. Lysosome c. Nucleus d. Peroxisome
a. ER
White blood cell and neuron differentiated a. Express different mRNA b. Have different proteins c. Do not transcribe for cells/proteins anymore
a. Express different mRNA
Which of the following changes is least likely to arise from point mutation in a regulatory region of a gene? a. A mutation that changes the time in an organism's life during which a protein is expressed. b. A mutation that eliminates the production of a protein in a specific cell type. c. A mutation that changes the subcellular localization of a protein. d. A mutation that increases the level of protein production in a cell.
c. A mutation that changes the subcellular localization of a protein.
What is the smallest unit of life? a. DNA b. Protein c. Cell d. Tissue
c. Cell
What is true about the Lac operon? a. The CAP is bound when there is excess glucose and lactose b. Lac operon turns on when the CAP is bound, even if the Lac repressor is bound c. Lac operon is on when there is excess lactose and low glucose level d. A low lactose level allows for the binding on CAP protein e. lactose levels have no effect on the Lac operon
c. Lac operon is on when there is excess lactose and low glucose level
Your friend works in a biotechnology company and has discovered a drug that blocks the ability of Ran to exchange GDP for GTP. What is the most likely effect of this drug on a nuclear transport receptors? a. Nuclear transport receptors would be unable to bind cargo. b. Nuclear transport receptors would be unable to enter the nucleus. c. Nuclear transport receptors would be unable to release their cargo in the nucleus. d. Nuclear transport receptors would interact irreversibly with the nuclear pore fibrils.
c. Nuclear transport receptors would be unable to release their cargo in the nucleus.
Your friend works in a biotechnology company and has discovered a drug that blocks the ability of Ran to exchange GDP for GTP. What is the most likely effect of this drug on nuclear transport? a. Nuclear transport receptors would be unable to bind cargo. b. Nuclear transport receptors would be unable to enter the nucleus. c. Nuclear transport receptors would be unable to release their cargo in the nucleus. d. Nuclear transport receptors would interact irreversibly with the nuclear pore fibrils.
c. Nuclear transport receptors would be unable to release their cargo in the nucleus.
