Cell Biology Exam 2 Questions And Correct Detailed Answers 100% Guaranteed Success.

protein family - correct answer a group of proteins that share a common evolutionary origin, reflected by their related functions and similarities in sequence or structure hierarchies - correct answer what are protein families arranged into? superfamily - correct answer a large group of distantly related proteins subfamily - correct answer a small group of closely related proteins filaments, sheets, and spheres - correct answer proteins can form larger structures such as what? actin filament - correct answer a chain of individual actin proteins bound to each other to form a helical chain ribosomes - correct answer comprised of rRNA and a complex of different proteins chromosomes - correct answer comprised of DNA and a complex of different proteins amino acid properties and structure - correct answer what determines the function of a protein? one or a few - correct answer because proteins are so specific, how many molecules will they interact with? ligand - correct answer the molecule that a protein interacts with (can be ion, small organic molecule, or macromolecule) weak, noncovalent bonds - correct answer how does a protein bind to its ligand? noncovalent bonds - correct answer hydrogen bonds, electrostatic interactions, van der Waals attractions, and hydrophobic interactions many bonds form simultaneously - correct answer since noncovalent bonds are weak, what must happen? binding site - correct answer the active site of a non-enzymatic protein tighter and longer - correct answer more noncovalent interactions cause what kind of protein-ligand interaction? antibodies - correct answer produced by the immune system to identify and neutralize foreign objects that enter the body (EX: bacteria and viruses) immunoglobulin - correct answer antibodies are part of which super family of proteins? antigen - correct answer large Y-shaped proteins that recognize a unique part of the foreign target similar - correct answer the general structure of all antibodies is what? antigen binding sites - correct answer small region at the tip of the protein that is extremely variable and allows millions of antibodies with slightly different structures allosteric regulation - correct answer the binding of a molecule (ligand) to a protein can cause a change in the shape of the protein; can increase the affinity of a protein for a second ligand; can switch the function of the protein on (increase) or off (decrease) sugar or amino acid - correct answer the ligand can take the form of a small molecule, such as what? or it can be an enzymatic modification to the existing protein what the protein acts upon - correct answer one protein can recruit another to a particular location and thus controls what? gene transcription - correct answer RNA polymerase interacts with DNA by regulatory proteins that recruit the polymerase to specific regions of the DNA for what? phosphorylation - correct answer the process of attaching a phosphate group covalently to one or more of a protein's amino acid side chains PO4- - correct answer phosphate group phosphate - correct answer can cause a major conformational change to a protein as a result of two negative charges dephosphorylation - correct answer the process of removing a phosphate group and returning the protein to its original structure Cdk2 (cyclin-dependent kinase 2) - correct answer an enzyme involved in regulation of the cell cycle; is inactive alone, but active when bound to the regulatory protein, cyclin, and phosphorylation of a specific amino acid; combined they cause a structural change around the active site alpha helix and a flexible loop - correct answer what are the two critical regions near the active site that are critical for a structural change by cyclin? absent - correct answer when cyclin is _____, the flexible loop is blocking the entrance to the active site and the alpha helix is found far away (contains a critical amino acid for enzymatic activity) threonine amino acid - correct answer full activation of Cdk requires a second allosteric change which is in the form of phosphorylation of a _____ found in the flexible loop CAK - correct answer phosphorylation is done by another kinase called what? (also activated by a phosphorylation event) more active - correct answer phosphorylation of threonine amino acid causes additional interactions with other amino acids found in different regions near the active site which cause an allosteric change and make the active site what? Cdk activation by cyclin - correct answer first the cyclin binds, partially activating Cdk, but also makes the flexible loop accessible for phosphorylation by CAK protein machines - correct answer individual proteins can come together to form larger complexes; each protein maintains its individual function, but allows for better coordination such that each function can be carried out in a specific series or sequence of events animation - correct answer pyruvate being converted into acetyl-CoA DNA - correct answer directs cell construction and operation and is the blueprint for producing proteins; directs which proteins are produced and when proteins - correct answer perform most of the cell's functions mRNA - correct answer ribonucleic acid intermediate; information encoded in DNA is ultimately used to specify the amino acid sequence of proteins central dogma of biology - correct answer DNA -- mRNA -- protein 50%; 50% - correct answer what percentage of the cell is DNA? what percentage of the cell is protein? chromosome - correct answer FUNCTIONS: allows DNA to be compacted to fit within cell, protects DNA from damage, allows DNA to be transmitted efficiently to both daughter cells during cell division, organizes the DNA and allows for regulation of DNA gene expression macromolecules - correct answer large molecules (polymers) comprised of smaller building block molecules (monomers) nucleotides - correct answer DNA and RNA are comprised of what? order - correct answer the _____ of the building blocks (nucleotides) determines their genetic or biochemical function weak and strong bonds - correct answer what plays a critical role in not only the synthesis of the polymers, but ultimately their structure, which determines their function? helical - correct answer a molecule of DNA is normally found in a ______ configuration antiparallel; complementary - correct answer DNA is composed of two, long _____ polynucleotide chains that are _____ to one another covalent bonds - correct answer the individual nucleotides are held together by what type of bonds? noncovalent; hydrogen - correct answer the overall structure of DNA is stabilized by _____ bonds that are held together by _____ bonds between complementary bases base stacking - correct answer flat surface of base pairs allows them to stack on top of each other yes - correct answer is DNA very stable?