DNA-RNA Amino Acid Protein
In this chapter we discuss DNA-RNA Amino Acid Protein.
DNA is a type of _____________
nucleic acid
__________ are found in virtually all cells
Nucleic acids
What is the function of nucleic acids?
To encode heritable information and pass it on from generation to generation
What three things make up nucleotides?
Phosphate, pentose sugar, and pyrimidine or purine base
What are the four bases in DNA?
Adenine, guanine, cytosine, and thymine
What are the four bases in RNA?
Adenine, guanine, cytosine, and uracil
How many strands does RNA have? DNA?
RNA is a single strand, DNA is double
Which base pairs with Adenine?
Thymine
Which base pairs with Guanine?
Cytosine
Where is DNA located?
In the Nucleus
What encases the DNA?
Chromosomes
How many chromosomes do humans have?
46. 23 pairs
Gene
Small segment of DNA that contains all the pairs of chromosomes
When was the double helix discovered?
1953
Who began the Human Genome project?
Francis S Collins
Hereditary information is stored in ______
DNA
The individual building blocks of DNA are called
Nucleotides
A DNA molecule consists of two nucleotide strands twisted into a
double helix
The ___________ of the DNA stands pair in a consistent fashion.
Bases
What is the RNA transcription for the DNA strand 5- GCT ATG CAT CGT – 3
5 – ACG AUG CAU AGC – 3
Which template DNA sequence would the short transcript 5- AUC CGU ACG -3 be derived from?
5- CGT ACG GAT -3
What is the complementary sequence for the following DNA sequence? 5- GCC ATC TCG AAT -3
5- ATT CGA GAT GGC -3
Assuming 100% reaction efficiency, how many DNA copies are created after the completion of four complete PCR cycles?
16
What is the function of DNA polymerase in the process of PCR?
It recognizes the primers and uses the available dNTPs to replicate the template DNA sequence
What type of mutation occurs when cytosine is completely mutated to guanin in the DNA sequence?
Nonsense
When using heat to denature a protein, which force is the first to be disrupted as temperature increases?
Hydrophobic interactions
Which term describes the order of amino acids in a peptide chain?
Primary structure
A commonly used technique for protein denaturation is adding an acid or a base to dramatically change the pH.
Which force is most impacted by this change in pH?
hydrophobic interactions
In which situation could a body function be disrupted by altering protein structure?
A mutation in aconitase blocks an essential step in aerobic metabolism
How can an alteration in protein structure lead to a disease state?
A mutation replaces an isoleucine with an aspartic acid in a transcription factor protein, which blocks the normal folding of the protein and its function in the expression of certain genes.
Which structural level shows the greatest difference when comparing denatured proteins with the normal version of the protein?
Tertiary
Frying an egg changes the egg white from a clear liquid to an opaque solid.
Which molecular change in the albumin protein causes this change in appearance?
Hydrophobic interactions form between denatured egg white proteins.
What is the driving mechanism of plaque formation in prion diseases?
Propagation of misfolding from one protein to another
Which feature of a protein made of a single polypeptide chain is most directly responsible for its function?
Three-dimensional structure
How does the Bohr effect describe the relationship between carbon dioxide levels, blood pH and the amount of oxygen bound to hemoglobin?
An increase in carbon dioxide production leads to a decrease in blood pH, causing hemoglobin to release oxygen more readily.
Which statement describes the binding of oxygen gas to a heme group?
The binding of oxygen gas to heme changes the structure of the heme group.
Which characteristic of myoglobin makes it an effective oxygen storage molecule?
It has a high affinity for oxygen.
At low O 2 concentrations, how does myoglobin’s affinity for O 2 relate to hemoglobin’s affinity for O 2?
Myoglobin has a much greater affinity for O 2 than hemoglobin does.
How does pH level promote the deoxygenated conformation of hemoglobin?
When pH lowers, excess H + binds to negatively charged side chains on hemoglobin and changes ionic bonds between subunits to favor the T-state
What is occurring in surrounding tissues as the amount of hemoglobin saturated with oxygen increases?
The amount of carbon dioxide decreases.
What is feedback inhibition?
Reversible, noncompetitive inhibition of an enzyme in a pathway by a product of that pathway
Which form of enzyme regulation is likely to be used by an organism to control the catalytic activity of its enzymes as it adapts to changes in available nutrients?
Feedback inhibition
How does heating beyond optimum temperature inactivate enzymes?
By changing the enzyme’s three-dimensional shape
What occurs in enzymes during the phenomenon of induced fit?
Substrate binding causes a conformational change.
Which portion of the enzyme does the substrate bind to?
Active site
Which type of inhibition occurs when a particular drug binds to the allosteric site of an enzyme and subsequently changes the enzyme’s structure?
Irreversible
What occurs immediately after the appropriate molecule enters the active site of an enzyme?
The enzyme binds the molecule to form an enzyme-molecule complex.
How is energy provided for ATP production during the final stage of aerobic metabolism?
Protons diffuse through a transmembrane protein.
What occurs in an otherwise healthy person whose diet has very few carbohydrates and high levels of fats?
Acetone is produced in the blood.
Which event is stimulated by release of glucagon into the blood?
Increase in lipolysis of triglycerides
What are the possible blood types of the parents of a patient with blood type AB?
A and B
Oxidative damage to DNA can often result in the alteration of a single nucleotide. Which DNA repair mechanism would repair this type of damage?
Base excision repair
Xeroderma pigmentosum (XP) is 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?
The mutation rate of all other genes is higher due to failure to repair.
Which reaction is responsible for the formation of polypeptides?
Dehydration
Which amino acid R group is charged?
The one with a pos or neg charge
Which amino acid R group is polar?
Non charged with Oxygen or Nitrogen
Which amino acid R group is nonpolar?
Non charged without Oxygen or Nitrogen
Which amino acid R group makes disulfide bonds?
A non polar amino acid with Cysteine (S)
Which amino acid R group makes ionic bonds?
Charged
What type of bond does a charged amino acid make?
Ionic bond
Which amino acid R group makes a disulfide bond?
A nonpolar with a Cysteine (S)
How does insulin impact carbohydrate metabolism?
It stimulates the uptake of glucose from the blood by cells in the body
How does insulin reduce blood glucose levels?
It increases the translocation of GluT4 transporters to the cell membrane
Approximately how many ATP molecules can be produced from a single molecule of glucose during aerobic metabolism
30
Which cellular condition prompts the cell to perform fermentation rather than the Krebs cycle?
Lack of O2
Which causes the symptoms of noninsulin-dependent (Type 2) diabetes?
There are not enough GluT4 transporters on plasma membranes
Which metabolic pathway involves coenzyme A, NAD, and FAD?
Beta Oxidation
Which molecule is pyruvate directly converted to under aerobic conditions?
Acetyl-CoA
How many molecules of lactate are required to produce one molecule of glucose
2
What is the role of oxygen in aerobic metabolism?
It acts as the final electron acceptor in the electron transport chain
Which pathway is triggered by increasing levels of epinephrine and provides a quick increase in available glucose?
glycogenolysis
Which type of molecule can be used in gluconeogenesis?
Amino acid
Which molecule acts as the primary signal for glycogen breakdown?
glucagon
What is a possible chemical formula for a momounsaturated fatty acid?
C8H14O2
What is the function of the class of lipids known as eicosanoids?
They act as signaling molecules
What is a glycolipid?
A Polymer of monosaccharides covalently attached to a membrane lipid
Which component of red blood cells determines blood type in the ABO blood group system?
glycolipids and glycoproteins
Which vitamin is not absorbed by phospholipid micelles?
Vitamin C
What occurs during the process of alternative splicing of mRNA?
Alternate combinations of exons within the same gene are linked together
Which type of mammalian DNA damage repair requires the presence of the chromosome that is homologous to the damaged chromosome?
Recombination
How many peptide bonds are present in a dipeptide?
1
Which force is most influential in determining the tertiary structure of a protein?
Hydrophobic effect
What is the name of large, functional protein structures composed of smaller proteins with multiple subunits?
Quaternary structure
Pepsin, the enzyme that catalyzes the breaking of peptide bonds, has the highest activity in the acidic environment of the stomach. what process is disrupted after a patient ingests excessive antacid that neutralizes the pH of the stomach?
Protein catabolism
In which situation could a body function be disrupted by altering protein structure?
A mutation in collagen results in weak bones
How can protein function be altered or lost in a disease state?
A deficiency of a specific metal ion inhibits an enzyme because it is required for its catalytic mechanism
Which structural level shows the greatest difference when comparing denatured proteins with the normal version of the protein?
Tertiary
Which level of protein structure is established through the dehydration synthesis of peptide bonds?
primary
Which situation would most likely lead to a permanent alteration of protein function?
A mutation that substitutes a hydrophobic amino acid with a hydrophilic amino acid
Identify the factors that favor the oxygenated form of hemoglobin
High pH, low carbon dioxide
Which metal ion is bound to the porphyrin ring in hemoglobin?
Iron
In what condition does hemoglobin bind to oxygen most readily?
Hemoglobin is already bound to one oxygen molecule
Which feature of hemoglobin makes it an effective oxygen transport molecule?
Its affinity for oxygen is regulated by pH
How does hemoglobin keep blood pH neutral during exercise?
Deoxygenated hemoglobin binds to excess H
What is a temporary modification to protein structure by kinases that alters enzyme function?
Phosphorylation
Which enzyme binding scenario best describes enzyme specificity and action?
An enzyme binds one substrate or closely related substrates to catalyze only one reaction.
Which change will likely increase the activity of an enzyme currently at optimal conditions?
Significantly increasing substrate concentration
Acetylcholine is broken down to acetate and choline by an enzyme calledacetylcholinesterase. Low levels of acetylcholine in the brain is associated with neurodegenerative disease. Which of the following medications could be used to treat neurodegeneration associated with low acetylcholine levels?
Noncompetitive inhibition
What stimulates beta-oxidation of fatty acids?
An increase in NAD concentration in the mitochondrial matrix
What is a function of cholesterol?
Maintains membrane fluidity
How would lipid production in a cell change in order to maintain fluidity of its cell membrane as it adapts to lower temperatures?
Produce lipids with shorter fatty acid chains.
How many ATP molecules are used in the conversion of pyruvate to glucose?
6
Long-distance runners often consume energy gels that are high in carbohydrates during their run. Which pathway is triggered by the intake of carbohydrates during exercise?
Glycolysis
Which cellular organelle required for the citric acid cycle and electron transport chain is not present in red blood cells?
Mitochondria
How would a genetic condition that inhibits the breakdown of glucose impact metabolism?
Activates glycogenesis
Where does substrate-level phosphorylation occur in the following metabolic pathway?
Step 3
What occurs during the biochemical process of glycation?
A covalent bond forms between a sugar and a protein or lipid.
Which complex polysaccharide acts as an energy-storing molecule in the liver?
Glycogen
Which components are involved in translation?
mRNA, tRNA, ribosome
What direction does DNA polymerase synthesize new DNA strands?
5 to 3
Which DNA repair mechanisms can fix the damage done by UV radiation in the form of thymine dimers?
nucleotide excision repair
What molecule fuels the activity of our bodies?
ATP
What are the three major steps in aerobic metabolism?
Glycolysis, Krebs cycle, and electron transport chain (ETC)
What are needed as inputs for the overall process of cellular respiration?
Sugar, oxygen
What are the outputs of cellular respiration?
ATP, carbon dioxide, water
How many molecules of ATP are produced per molecule of glucose during aerobic metabolism?
30
C6H12O6 is what molecule?
Glucose
Where does glycolysis take place?
cytoplasm
What is glycolysis?
breaking down glucose
What is breaking down glucose called?
Glycolysis
What are the inputs for glycolysis?
Glucose, 2 ATP, 4 ADP, and 2 NAD+
What is glucose converted to during glycolysis?
Pyruvate
Where does the krebs cycle occur?
the matrix
What are the inputs for the krebs cycle?
Acetyl CoA, NAD+, FAD, and GDP
What are the outputs from the Krebs cycle?
CO2, NADH, FADH2, and GTP
What are the inputs for ETC?
NADH, FADH2, O2, Pi, and ADP
What are the outputs for ETC?
NAD+, FAD, H2O, and ATP
Where does ETC take place?
Inner membrane
What must be present in order for pyruvate to enter the matrix and start the Krebs cycle?
Oxygen
What does pyruvate convert into to start the krebs cycle?
Acetyl CoA
During the ETC what is transferred through to the intermembrane space by the NAD and FAD?
H+
What is transferred back into the matrix during ETC from NAD and FAD?
H20
What allows the protons to move back into the matrix?
The ATP synthase
What is caused by the protons moving back into the Matrix
ATP
What happens to NADH when it gives up a proton?
It becomes NAD+
What happens when Oxygen is not present?
The ETC cannot occur
What are the steps of anaerobic metabolism
Glycolysis, fermentation
When does the body use anaerobic metabolism?
When there is no oxygen available, like during exercise
What is glycogen?
A chain of glucose
What is the process of making glycogen?
Glycogenesis
What is the function of glucagon?
It tells your body to release glycogen back into the blood stream when glucose levels are low
What is the process of breaking glycogen back into glucose?
Glycogenolysis
Putting molecules together in chains is called ———–.
Anabolism
Breaking the chains back into individual molecules is called _________
Catabolism
A chain of fatty acids is called __________
Triglyceride
Fatty acids form triglycerides through which process?
Lipogenesis
Triglycerides are broke back into fatty acids during which process?
Lipolysis
Amino acids bind together in a chain to form ______.
Protein
Amino acids form proteins through which process?
Dehydration synthesis
Proteins are broke down into amino acids during which process?
Hydrolytic cleavage
What is a glycated protein?
Glucose + protein
What causes neuropathy in DM?
AGEs stick to the walls of the vessels and inhibit circulation
How many carbons does each acetyl-CoA have?
2
How do you determine how many rounds of beta oxidation are needed?
Divide the total number of carbons by 2, then subtract one.
What type of bonds hold the amino acid together?
Peptid bonds
Which structure is the R group interactions?
Tertiary
What can disrupt a hydrophobic interaction?
Increase temperature
What can disrupt a hydrogen bond?
Increase temperature or change in pH
What can disrupt an ionic bond?
Change in pH or adding salt