mastering physiology ch 2
What is the correct order for the following list of steps for initiating translation? 1. Binding of initiator tRNA to mRNA 2. Binding of large ribosomal subunit to mRNA 3. Binding of small ribosomal subunit to mRNA 4. Binding of a 2nd tRNA with its amino acid to the A site 5. Formation of covalent bond between methionine and second amino acid 3, 2, 1, 4, 5 1, 3, 2, 4, 5 1, 2, 3, 4, 5 2, 3, 1, 4, 5 3, 1, 2, 4, 5
3, 1, 2, 4, 5
What are the three components of a nucleotide? deoxyribonucleic acid, base pairs, phosphate/sugar backbone ribonucleic acid, base pairs, phosphate backbone 5-carbon carbohydrate, phosphate, nitrogenous base pentose sugar, 5-carbon carbohydrate, phosphate pentose, nitrogenous base, phosphorus
5-carbon carbohydrate, phosphate, nitrogenous base
What are the tRNA binding sites on the ribosome called? T and R sites A and P sites translation sites nucleotide complement sites proteogenic sites
A and P sites
________ act(s) as the precursor to steroid molecules, many of which function as hormones. Saturated fatty acids Eicosanoids Cholesterol Unsaturated fatty acids Phospholipids
Cholesterol
Components of the electron transport chain are found in what region of a mitochondrion? cristae intermembrane space inner mitochondrial membrane outer membrane matrix
inner mitochondrial membrane
All of the following are basic components of proteins EXCEPT nitrogen. carbon. oxygen. potassium. hydrogen.
potassium
The promoter sequence of the gene is recognized by ________, which initiates transcription. helicase RNA polymerase gyrase ligase DNA polymerase
RNA polymerase
What is the level of structure that corresponds to the sequence and number of amino acids in the polypeptide chain? primary secondary tertiary quaternary quinary
primary
Where does RNA polymerase bind to initiate transcription? leader sequence hormone response element initiation factor P subunit of the ribosome promoter sequence
promoter sequence
Aspirin and ibuprofen both block the enzyme cyclooxygenase from changing arachadonic acid, found in the phospholipid bilayer, into what? sterols bile salts surfactant prostaglandins leukotrienes
prostaglandins
Which of the following packages proteins into transport vesicles? smooth endoplasmic reticulum Golgi apparatus lysosomes peroxisomes mitochondria
smooth endoplasmic reticulum
The process whereby a complementary mRNA is produced from a DNA template is called transcytosis. transoperon. translation. post-translational modification. transcription.
transcription
Which of the following is not a fate of proteins produced by the cells?. secretion out of the cell translation into tRNA cytoplasmic localization for intracellular signaling incorporation into the plasma membrane
translation into tRNA
The initiator codon is composed of the sequence CCG. AUG. AAC. UUG. CCC.
AUG
________ are molecules whose general structure includes a central carbon with a carboxyl group, an amine group, a hydrogen molecule, and a residual (R) group. Proteins Amino acids Nucleotides Lipids Carbohydrates
Amino acids
Which of the following is true regarding the differences between RNA and DNA? DNA consists of a single strand of nucleotides and RNA consists of two strands which form a double helix. RNA functions in the storage of genetic information, whereas DNA functions in the expression of genetic information. DNA is located in the nucleus of a cell, whereas RNA is located both in the nucleus and in the cytoplasm. Adenine is present in DNA only. Uracil is present in RNA instead of adenine.
DNA is located in the nucleus of a cell, whereas RNA is located both in the nucleus and in the cytoplasm.
What enzyme catalyzes the reaction whereby nucleotides are added to the polynucleotide chain during replication? histone DNA polymerase RNA polymerase helicase chromatin
DNA polymerase
Which enzyme is used to copy the DNA genetic code during replication? DNA polymerase ribosome RNA polymerase DNA repair enzymes
DNA polymerase
________ are modified fatty acids that function in intercellular communication and include prostaglandins and thromboxanes. Triglycerides Eicosanoids Saturated fatty acids Steroids Phospholipids
Eicosanoids
________ is a polysaccharide found in animal cells, whereas ________ is a polysaccharide found in plants that can be degraded by humans. Galactose : cellulose Lactose : starch Glycogen : starch Glycogen : cellulose Galactose : starch
Glycogen : starch
Which of the following packages proteins into secretory vesicles? smooth endoplasmic reticulum Golgi apparatus peroxisomes mitochondria lysosomes
Golgi apparatus
Which of the following correctly describes glycogen? It contains the genetic information found in cells. It is an important storage polysaccharide found in animal tissues. It serves as a structural component of human cells. It forms the regulatory molecules known as enzymes. It helps to protect vital organs from damage.
It is an important storage polysaccharide found in animal tissues.
Upon completion of translation, how is a newly synthesized protein appropriately directed to the organelle in which it functions? The mRNA shuttles the newly formed protein to the appropriate organelle. The very first amino acid dictates protein localization. The tRNA "transfers" the newly formed protein to the appropriate organelle. Leader sequence amino acids within the new protein serve as an address tag.
Leader sequence amino acids within the new protein serve as an address tag.
Which of the following statements is true of lipids? If a molecule is amphipathic, it cannot be a lipid. The most common steroid is testosterone. Triglycerides are formed from a glycerol backbone and two fatty acids. Lipids are hydrophobic molecules.
Lipids are hydrophobic molecules.
Which of the following molecules will dissolve readily in water? triglyceride NaCl cholesterol fatty acid C6H14
NaCl
________ are molecules that form the bilayer of cell membranes and micelles. Saturated fatty acids Steroids Phospholipids Eicosanoids Triglycerides
Phospholipids
During transcription, protein is synthesized from RNA in the cytoplasm. RNA is synthesized from DNA in the nucleus. protein is synthesized from RNA in the nucleus. DNA is synthesized from DNA in the nucleus. RNA is synthesized from DNA in the cytoplasm.
RNA is synthesized from DNA in the nucleus.
________ are molecules composed of a glycerol and three fatty acids. Saturated fatty acids Steroids Phospholipids Triglycerides Eicosanoids
Triglycerides
What causes DNA to uncoil during transcription? binding of helicase to the DNA binding of tRNA to the initiator codon binding of ubiquitin to the DNA binding of DNA polymerase to the leader sequence binding of RNA polymerase to the promoter sequence
binding of RNA polymerase to the promoter sequence
Which of the following best describes C6H12O6? disaccharide blood sugar glycogen table sugar
blood sugar
Which of the following is NOT one of the types of RNA synthesized during the process of transcription? mRNA rRNA cRNA tRNA
cRNA
Formation of peptide bonds occurs by condensation reactions between the ________ group of one amino acid and the ________group of another. fatty acid : glycerol glucose : glucose fatty acid : glycerol amino acid : amino acid carboxyl : amino acid amino
carboxyl : amino acid amino
Each amino acid differs from others only by the number of peptide bonds in the molecule. size of its amino group. characteristic of its R group. number of central carbon atoms. number of its carboxyl groups.
characteristic of its R group.
What interaction between the phosphate and the carbohydrate of a nucleotide holds the backbone of a DNA strand together? ionic bonds van der Waals forces disulfide bridges hydrogen bonds covalent bonds
covalent bonds
When proteins are synthesized by ribosomes on the rough endoplasmic reticulum, where does the translation begin? smooth endoplasmic reticulum cytosol rough endoplasmic reticulum Golgi apparatus nucleus
cytosol
Which of the following is NOT a polymer? ribonucleic acid (RNA) a saturated fatty acid 30-amino acid polypeptide glucose
glucose
Based on what you know about the chemical properties of carbohydrates, proteins, and lipids, which of the following is an amphipathic structure the enzyme used to digest protein glycoprotein lipoprotein DNA
lipoprotein
The initiator codon, that originates translation, codes for the amino acid proline. arginine. tyrosine. methionine. leucine.
methionine
In which of the following organelles is genomic material stored? nucleus rough endoplasmic reticulum lysosomes ribosome
nucleus
Which of the following correctly describes the quaternary structure of a protein? a simple chain of amino acids only in proteins containing more than one polypeptide chain beta pleated sheets or alpha helixes a folded pattern formed by interactions between the R groups of amino acids
only in proteins containing more than one polypeptide chain
The most common elements found in biomolecules are carbon, hydrogen, nitrogen, and phosphorous. potassium. oxygen. calcium. chlorine.
oxygen
Which of the following are NOT embedded in the lipid bilayer at all? peripheral proteins transmembrane proteins connexons cadherins integral proteins
peripheral proteins
What chemical property is given to a biomolecule with a hydroxyl (--OH) functional group? base acid polar Amphipathic
polar
The amphipathic property of phospholipids can be described as a nonpolar region facing the outside and a polar region facing the inside of a cell. polar region that dissolves in water and a nonpolar region that repels water. single polar region that is miscible in aqueous solution. single nonpolar region that is not miscible in aqueous solution. nonpolar region that dissolves in water and a polar region that face one another.
polar region that dissolves in water and a nonpolar region that repels water.
A fatty acid that contains three double bonds in its carbon chain is said to be polyunsaturated. saturated. polysaturated. monounsaturated. hypersaturated.
polyunsaturated
During translation, ________ is synthesized in the ________. protein : nucleus DNA : nucleus RNA : nucleus protein : cytoplasm RNA : cytoplasm
protein : cytoplasm
An acid is a molecule that acts as a(n) proton donor. hydroxide donor. hydrogen acceptor. proton acceptor. electron donor.
proton donor.
What is the correct level of structure for proteins containing more than one polypeptide chain? primary secondary tertiary quaternary quinary
quaternary
What two types of molecules make up ribosomes? phospholipids and RNA mRNA and tRNA rRNA and tRNA rRNA and proteins proteins and phospholipids
rRNA and proteins
Which of the following organelles is classified as nonmembranous? lysosomes ribosomes mitochondria Golgi apparatus
ribosomes
Which of the following translates mRNA into proteins? peroxisomes mitochondria ribosomes Golgi apparatus
ribosomes
Alpha-helixes and β-pleated sheets are examples of ________ structures of a protein. primary secondary tertiary quaternary pentanary
secondary
Hydrogen bonding between the amino hydrogen of one amino acid and the carboxyl oxygen of another is responsible for which of the following? holding the two strands of DNA together by the law of complementary base pairing twisting the DNA into a helical structure primary protein structure secondary protein structure tertiary protein structure
secondary protein structure
Which of the following is NOT a possible destination for proteins that are completely synthesized on ribosomes free in the cytosol? nucleus secreted from the cell mitochondrion remains in cytosol peroxisome
secreted from the cell
The membrane of the rough endoplasmic reticulum is continuous with what other membrane(s)? matrix plasma membrane Golgi apparatus smooth endoplasmic reticulum and nuclear envelope nucleolus and nuclear pore
smooth endoplasmic reticulum and nuclear envelope
What is the level of structure that corresponds to the chemical interactions between R groups within the same polypeptide chain? primary secondary tertiary quaternary quinary
tertiary
Which of the following processes is NOT a post-translational modification that occurs in the endoplasmic reticulum or Golgi apparatus to make proteins functional? the cleavage of excess amino acids the removal of the leader sequence the addition of carbohydrates the addition of lipids the addition of more amino acids
the addition of more amino acids
What type of integral membrane protein spans the membrane, thereby allowing part of it to face the cytosol and another part to face the extracellular fluid? transmembrane protein glycoprotein paramembrane protein peripheral membrane protein steroid receptor
transmembrane protein
What is a glycerol with 3 fatty acids attached? saturated fat phospholipid eicosanoid glycerolipid triglyceride
triglyceride
