WGU Biochemistry OA 2023
Bohr Effect chart (low pH) - correct answer C- High CO2
H- High H+
A- Acidic
R-Release of O2(rt. Shift)
T- tense state
... [Show More] (in tissues)
Primary structure - correct answer Sequence of amino acids that make up a protein
Secondary Structure - correct answer Sequence of amino acids fold.
Tertiary Structure - correct answer -more folding in a 3D shape.
-R groups (side chains)
Quaternary Structure - correct answer Protein has more than 1 polypeptide chain.
Chemical reaction - correct answer -absorb and release energy
-activation energy
-energy is released (heat & light) when bonds are broken.
Exothermic reaction - correct answer Exo=to release
Thermo=heat
-chemical reaction that releases more energy than it absorbs (as heat & light)
Example of exothermic reaction - correct answer Cellular respiration- breaks down glucose to make cellular energy
Endothermic reaction - correct answer Endo=absorb
Thermos=heat
-absorbs more energy than it releases
Example of endothermic reaction - correct answer Photosynthesis- takes in light to break down to create glucose
Catalyst - correct answer Substance that will decrease the activation energy needed to start a chemical reaction
Enzymes - correct answer -catalysts used by cells
-increase the rate of chemical reaction
-specific to substrates
Enzyme structure - correct answer -they are proteins
-twist, fold, bend to final shape
-shape attracts specific molecules
Substrate - correct answer Molecules that bind to the enzyme
Active site - correct answer -location on enzyme where substrate binds
Function of DNA polymerase in process of PCR. - correct answer -increase expression
-2 genes
-SIRT1 & SIRT2
Function of a molecule - correct answer Structural component of the lipid bilayer
How would lipid production in a cell change in order to maintain fluidity of its cell membrane as it adapts to lower temperatures? - correct answer Produce lipids with shorter fatty acid chains
Function of cholesterol - correct answer Maintains membrane fluidity
Lipid (fat) soluble vitamins - correct answer A, D, E, K
What stimulates beta-oxidation of fatty acids? - correct answer An increase in NAD+ concentration in the mitochondrial matrix
What occurs in an otherwise healthy person whose diet has very few carbs and high levels of fats? - correct answer Acetone is produced in the blood
Amino acids - correct answer -Non-polar (hydrophobic)
-Polar charged
-Polar uncharged
Which type of mammalian DNA damage repair requires the presence of the chromosome that is homologous to the damaged chromosome? - correct answer Recombination
Xeroxerma Pigmentosum (XP) - correct answer A recessive genetic disease that occurs when one or more of the genes that perform nucleotide excision repair are nonfunctional
Why do XP patients have a much higher incidence of skin cancer than the general population? - correct answer The mutation of all other genes is higher due to failure to repair.
Assuming 100% reaction efficiency, how many DNA copies are created after the completion of 4 complete PCR cycles? - correct answer 16
What is the function of DNA polymerase in the process of PCR? - correct answer It recognizes the primers and uses the available dNTPs to replicate the template DNA sequence.
What difference in the regions of the SIRT1 & SIRT2 genes in people addicted to cocaine increases their expression? - correct answer The nucleosomes become more widely spaced.
What occurs during the process of alternative splicing of RNA? - correct answer Alternate combinations of Exons within the same gene are linked together.
Polypeptides - correct answer -functional proteins
-made of folded up polymers
Elements - correct answer Substance that cannot be broken down into another substance by chemical reaction.
Ionic bond - correct answer Actions share + & - charge
Covalent bond - correct answer When atoms share electrons
Hydrogen bond - correct answer Forms when portion of a polar molecule that is partially positive interacts with portion of a polar molecule that is partially negative
Van der Waals interactions - correct answer Occur due to random, transient movements of electrons that at any given instant, give molecules regions of + & - charges.
Amino acid - correct answer -has amino group (-NH2)
-& a carbonyl group (-COOH)
-cx. Based on side chains
Elevated levels of AST & ALT - correct answer -indicates liver damage
(When damaged, their protein contents can spill into blood stream)
Which level of protein structure is disrupted through the hydrolysis of peptide bonds? - correct answer Primary
Sickle cell disease - correct answer Caused by mutation in the Hgb-beta gene. (Causes cells to become rigid, sticky, misshapen.)
Which force is most influential in determining the secondary structure of a protein? - correct answer Hydrogen bonding
Hydrophobic effect - correct answer Tendency of non polar substances to aggregate in an aqueous solution & exclude water molecules.
Hydrophobic interaction - correct answer Mutation of gene for protein that leads to substitution of no polar amino acid with charged amino acid
Dopamine - correct answer -neurotransmitter
-variety of functions (including motor control)
Parkinson's = decreases dopamine. Sinemet helps by increasing dopamine levels.
Lactose breaks down into : - correct answer Glucose and galactose
Frameshift mutation - correct answer -insertion or deletion of 1 or 2 nucleotides
Missense mutation - correct answer -substitution of one amino acid for another
-results in 10 different amino acids or 10 missense mutations
Nonsense mutation - correct answer -premature stop codon incorporated into the sequence
-leads to a shorter protein
Carbohydrates - correct answer -linear
-CH2O formula
-energy=glucose
-structure=cellulose
Lipids - correct answer -energy storage
-signaling
-high amount of C
DNA - correct answer -twisted ladder
-double helix
-in nucleus
-deoxyribose
-bases= Anine, Thymine, Cytosine, Guarine
-in all molecules
-have nucleotides
RNA - correct answer -plays "messenger"
-in & outside nucleus
-ribose
-Adenine, Uracil, Guarine, Cytosine
-mRNA=messenger (takes message to ribosome)
-rRNA=ribosomal RNA
-tRNA=transfers amino acids
Transcription - correct answer -comes first! Transcribes DNA into message.
(RNA polymerase will connect complementary bases. mRNA can go out of nucleus to attach to ribosome of rRNA)
How do rising blood CO2 levels promote the deoxygenated confirmation of hemoglobin? - correct answer CO2 reacts with H2O in the blood & decreases pH, which promotes the dome confirmation of the heme group.
How does hemoglobin keep blood pH neutral during exercise? - correct answer Deoxygenated hemoglobin binds to excess H+
What is occurring in surrounding tissues as the amount of hemoglobin saturated with oxygen increases? - correct answer The concentration of hydrogen ions decreases.
Translation - correct answer -2nd step
-builds protein
(tRNA leaves behind its amino acid, built chain of amino acids)
Factors that favor the oxygenated form of hemoglobin: - correct answer -increased pH
-decreased CO2
Which metal ion is bound to the porphyrin ring in hemoglobin? - correct answer Iron [Show Less]