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.