Ch. 2 HW
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, 1, 2, 4, 5
What are the three components of a nucleotide? - ribonucleic acid, base pairs, phosphate backbone - 5-carbon carbohydrate, phosphate, nitrogenous base - deoxyribonucleic acid, base pairs, phosphate/sugar backbone - 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? -translation sites - proteogenic sites - T and R sites - A and P sites - nucleotide complement sites
A and P sites
The initiator codon is composed of the sequence: - UUG. - AUG. - CCC. - AAC. - CCG.
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 - Carbohydrates - Nucleotides - Lipids - Amino acids
Amino acids
The synthesis of proteins from amino acids is an example of __________. - metabolism - catabolism - anabolism - embolism
Anabolism
Biomolecules are molecules that are synthesized by living organisms and contain __________ atoms.: - carbon (C) - sodium (Na) - nitrogen (N) - oxygen (O)
Carbon ( That's right. For example, the general chemical formula for carbohydrates is (CH2O)n.)
________ act(s) as the precursor to steroid molecules, many of which function as hormones. - Unsaturated fatty acids - Eicosanoids - Phospholipids - Cholesterol - Saturated fatty acids
Cholesterol
When proteins are synthesized by ribosomes on the rough endoplasmic reticulum, where does the translation begin? - rough endoplasmic reticulum - nucleus - smooth endoplasmic reticulum - cytosol - Golgi apparatus
Cytosol
Which of the following is true regarding the differences between RNA and DNA? - Adenine is present in DNA only. Uracil is present in RNA instead of adenine. - RNA functions in the storage of genetic information, whereas DNA functions in the expression of genetic information. - DNA consists of a single strand of nucleotides and RNA consists of two strands which form a double helix. - DNA is located in the nucleus of a cell, whereas RNA is located both in the nucleus and in the cytoplasm.
DNA is located in the nucleus of a cell, whereas RNA is located both in the nucleus and in the cytoplasm. ( This is true. Recall that mRNA is formed in the nucleus, but eventually is transported out of the nucleus into the cytoplasm. Additionally, tRNA and rRNA are both found in the cytoplasm, where they participate in translation.)
What enzyme catalyzes the reaction whereby nucleotides are added to the polynucleotide chain during replication? - histone - chromatin - helicase - RNA polymerase - DNA polymerase
DNA polymerase
Which enzyme is used to copy the DNA genetic code during replication? - DNA repair enzymes - ribosome - RNA polymerase - DNA polymerase
DNA polymerase
________ are modified fatty acids that function in intercellular communication and include prostaglandins and thromboxanes. - Saturated fatty acids - Steroids - Eicosanoids - Phospholipids - Triglycerides
Eicosanoids
Which of the following is a mechanism by which proteins are secreted from a cell? - receptor-mediated - endocytosis - exocytosis - ubiquination - phagocytosis
Exocytosis ( Exocytosis involves the release of proteins from vesicles to the extracellular fluid.)
________ is a polysaccharide found in animal cells, whereas ________ is a polysaccharide found in plants that can be degraded by humans.: - Galactose : starch - Glycogen : cellulose - Glycogen : starch - Galactose : cellulose - Lactose : starch
Glycogen : starch
Which of the following packages proteins into secretory vesicles? - Golgi apparatus - lysosomes - mitochondria - smooth endoplasmic reticulum - peroxisomes
Golgi apparatus
Which of the following correctly describes glycogen? - It serves as a structural component of human cells. - It is an important storage polysaccharide found in animal tissues. - It helps to protect vital organs from damage. - It forms the regulatory molecules known as enzymes. - It contains the genetic information found in cells.
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? - Upon completion of translation, how is a newly synthesized protein appropriately directed to the organelle in which it functions? - 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. - The mRNA shuttles the newly formed protein to the appropriate organelle.
Leader sequence amino acids within the new protein serve as an address tag.
Which of the following statements is true of lipids?: - Lipids are hydrophobic molecules. - The most common steroid is testosterone. - Triglycerides are formed from a glycerol backbone and two fatty acids. - If a molecule is amphipathic, it cannot be a lipid.
Lipids are hydrophobic molecules. ( This is true. Lipids are biomolecules of mostly carbon and hydrogen atoms linked together with nonpolar covalent bonds--making them hydrophobic.)
Which of the following molecules will dissolve readily in water?: - NaCl - triglyceride - cholesterol - C6H14 - fatty acid
NaCl
In which of the following organelles is genomic material stored? - ribosome - rough endoplasmic - reticulum - nucleus - lysosomes
Nucleus
The most common elements found in biomolecules are carbon, hydrogen, nitrogen, and: - potassium. - phosphorous. - oxygen. - calcium. - chlorine.
Oxygen
________ are molecules that form the bilayer of cell membranes and micelles. - Steroids - Saturated fatty acids - Triglycerides - Phospholipids - Eicosanoids
Phospholipids
What is the correct level of structure for proteins containing more than one polypeptide chain? - primary - secondary - tertiary - quaternary - quinary
Quaternary
During transcription, - RNA is synthesized from DNA in the nucleus. - RNA is synthesized from DNA in the cytoplasm. - DNA is synthesized from DNA in the nucleus. - protein is synthesized from RNA in the nucleus. - protein is synthesized from RNA in the cytoplasm.
RNA is synthesized from DNA in the nucleus.
The promoter sequence of the gene is recognized by ________, which initiates transcription. - helicase - RNA polymerase - ligase - DNA polymerase - gyrase
RNA polymerase
Mature red blood cells (erythrocytes) do not have a nucleus. Can erythrocytes divide and form daughter cells? - Red blood cells cannot divide because their DNA instructs them not to. - Red blood cells cannot divide and generate daughter cells because they have no DNA. - Red blood cells can divide, even without a nucleus. - Red blood cells cannot divide because they are not actually cells.
Red blood cells cannot divide and generate daughter cells because they have no DNA. ( DNA is housed in the nucleus. A cell with no nucleus contains no DNA. It just so happens that mature erythrocytes cannot and do not undergo mitosis.)
Which of the following organelles is classified as nonmembranous? - lysosomes - ribosomes - Golgi apparatus - mitochondria
Ribosomes
Which of the following translates mRNA into proteins? - peroxisomes - mitochondria - Golgi apparatus - ribosomes
Ribosomes
Alpha-helixes and β-pleated sheets are examples of ________ structures of a protein. - primary - secondary - tertiary - quaternary - pentanary
Secondary
What level of structure is caused when the hydrogen bonds between the amino hydrogen of one amino acid and the carboxyl oxygen of another amino acid is formed? - primary - secondary - tertiary - quaternary - quinary
Secondary
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 statements best describes the plasma membrane? - Cholesterol makes up the largest portion of the plasma membrane bilayer. - The plasma membrane is described as an impermeable barrier. - The plasma membrane is identical to the nuclear membrane. - The plasma membrane is a flexible and dynamic structure.
The plasma membrane is a flexible and dynamic structure.
Which of the following statements about the plasma membrane is FALSE? - The plasma membrane is a rigid, nonflexible structure. Phospholipids make up a large portion of the plasma membrane bilayer. - The plasma membrane is described as a "fluid mosaic." - The plasma membrane separates the cell from the extracellular fluid.
The plasma membrane is a rigid, nonflexible structure.
Which of the following statements concerning hydrogen bonds is FALSE?: - They are responsible for many of the unique properties of water. - They are important forces for tertiary structure of proteins. - They are strong attractive forces between hydrogen atoms and negatively charged atoms. - They can occur within a single molecule. - They can form between neighboring molecules.
They are strong attractive forces between hydrogen atoms and negatively charged atoms.
What is a glycerol with 3 fatty acids attached? - saturated fat - glycerolipid - triglyceride - eicosanoid - phospholipid
Triglyceride
________ are molecules composed of a glycerol and three fatty acids.: - Phospholipids - Eicosanoids - Triglycerides - Steroids - Saturated fatty acids
Triglycerides
An anticodon is - the code for a particular amino acid. - the strand of DNA used to create mRNA. - the complement to the complement of the gene. - a three-nucleotide series on tRNA that is complementary to the - mRNA to which it binds. the stop signal that does not code for an amino acid.
a three-nucleotide series on tRNA that is complementary to the mRNA to which it binds.
What causes DNA to uncoil during transcription? - binding of DNA polymerase to the leader sequence - binding of RNA polymerase to the promoter sequence - binding of helicase to the DNA - binding of ubiquitin to the DNA - binding of tRNA to the initiator codon
binding of RNA polymerase to the promoter sequence
Which of the following best describes C6H12O6?: - disaccharide - blood sugar - table sugar - glycogen
blood sugar ( Yes. C6H12O6 is the formula for glucose, which is also called blood sugar.)
Which of the following is NOT one of the types of RNA synthesized during the process of transcription? - cRNA - tRNA - rRNA - mRNA
cRNA
Formation of peptide bonds occurs by condensation reactions between the ________ group of one amino acid and the ________group of another. - glucose : glucose - fatty acid : glycerol - 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 its carboxyl groups. - characteristic of its R group. - size of its amino group. - number of central carbon atoms. - number of peptide bonds in the molecule.
characteristic of its R group.
What interaction between the phosphate and the carbohydrate of a nucleotide holds the backbone of a DNA strand together? - hydrogen bonds - ionic bonds - van der Waals forces - covalent bonds - disulfide bridges
covalent bonds
Which of the following is NOT a polymer? - 30-amino acid polypeptide - ribonucleic acid (RNA) - glucose - a saturated fatty acid
glucose ( Glucose is a monosaccharide, not a polymer.)
Components of the electron transport chain are found in what region of a mitochondrion? - cristae - outer membrane - inner mitochondrial membrane - intermembrane space matrix
inner mitochondrial membrane
Which of the following is NOT a monosaccharide? - glucose - lactose - galactose - fructose - deoxyribose
lactose
Which of the following molecules is a disaccharide? - glycogen - galactose - lactose - fructose - glucose
lactose
Based on what you know about the chemical properties of carbohydrates, proteins, and lipids, which of the following is an amphipathic structure? - DNA - glycoprotein - lipoprotein - the enzyme used to digest protein
lipoprotein ( The lipid portion of this molecule is nonpolar and the protein portion is polar. Therefore, this is an amphipathic molecule.)
The initiator codon, that originates translation, codes for the amino acid: - leucine. - arginine. - methionine. - proline. - tyrosine. - Previous An
methionine
Which of the following correctly describes the quaternary structure of a protein?: - beta pleated sheets or alpha helixes - a simple chain of amino acids - only in proteins containing more than one polypeptide chain - a folded pattern formed by interactions between the R groups of amino acids
only in proteins containing more than one polypeptide chain ( Yes. Quaternary protein structures exist only in proteins containing multiple polypeptides put together. Hemoglobin and insulin are good examples of this.)
Which of the following are NOT embedded in the lipid bilayer at all? - cadherins - peripheral proteins - transmembrane proteins - integral proteins - connexons
peripheral proteins
What chemical property is given to a biomolecule with a hydroxyl (--OH) functional group?: - Amphipathic - polar - base - acid
polar ( Yes. Hydroxyl functional groups give at least a portion of the biomolecule a polar characteristic--making them at least partially water-soluble. Alcohol, for example, is water soluble)
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 nonpolar region that is not miscible in aqueous solution. - single polar region that is 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: - polysaturated. - hypersaturated. - polyunsaturated. - saturated. - monounsaturated.
polyunsaturated.
All of the following are basic components of proteins EXCEPT - hydrogen. - potassium. - carbon. - nitrogen. -oxygen.
potassium
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 - initiation factor - hormone response element - promoter sequence - P subunit of the ribosome
promoter sequence
Aspirin and ibuprofen both block the enzyme cyclooxygenase from changing arachadonic acid, found in the phospholipid bilayer, into what? - bile salts - sterols - prostaglandins - leukotrienes - surfactant
prostaglandins
During translation, ________ is synthesized in the ________.: - DNA : nucleus - protein : cytoplasm - protein : nucleus - RNA : cytoplasm - RNA : nucleus
protein : cytoplasm
An acid is a molecule that acts as a(n) - proton acceptor. - electron donor. - proton donor. - hydroxide donor. - hydrogen acceptor.
proton donor
What two types of molecules make up ribosomes? - rRNA and proteins - phospholipids and RNA - rRNA and tRNA - mRNA and tRNA - proteins and phospholipids
rRNA and proteins
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 - mitochondrion - peroxisome - secreted from the cell - remains in cytosol
secreted from the cell
The membrane of the rough endoplasmic reticulum is continuous with what other membrane(s)? - Golgi apparatus - smooth endoplasmic reticulum and nuclear envelope - matrix - plasma membrane - nucleolus and nuclear pore
smooth endoplasmic reticulum and nuclear envelope
Which of the following packages proteins into transport vesicles? - peroxisomes - Golgi apparatus - lysosomes - smooth endoplasmic reticulum - mitochondria
smooth endoplasmic reticulum
The strand of DNA that gets transcribed to mRNA is called the: - promoter sequence. - exon strand. - template strand. - ribophorin. - intron strand.
template strand.
The process whereby a complementary mRNA is produced from a DNA template is called: - transcription. - translation. - transoperon. - post-translational modification. - transcytosis.
transcription
Which of the following is not a fate of proteins produced by the cells?. - secretion out of the cell - cytoplasmic localization for intracellular signaling - translation into tRNA - incorporation into the plasma membrane
translation into tRNA ( Proteins are produced by translation, which involves tRNA.)
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? - paramembrane protein - peripheral membrane protein - steroid receptor - glycoprotein - transmembrane protein
transmembrane protein
Hydrolytic reactions are when - the bond between two molecules is broken through the splitting of a water molecule, thereby creating two new bonds with the H and OH of that water in its place. - the bond between two molecules is broken, resulting in the removal of a water molecule. - two molecules are joined together, resulting in the removal of a water molecule. - water is removed from the cell. - two molecules are joined together by adding a water molecule.
two molecules are joined together by adding a water molecule.
