Bio 1213 Practice Questions

When three phosphate groups are covalently attached to adenosine, __________ is formed.

ATP

What is ATP's importance in the cell?

ATP stores the potential to react with water, thereby removing a phosphate group and releasing energy for cellular processes.

Nitrogenous bases are classified as either purines or pyrimidines. Examples of purines are __________.

Adenine and guanine

Which of the following is found in all amino acids?

Both -COOH and -NH2

Life's most important Molecules

Carbon, Nitrogen, Oxygen, Hydrogen, Phosphate, and sulfer

The chemical group that acts as an acid is the __________.

Carboxyl Group (-COOH)

Which of the following is a polymer?

Cellulose, a plant cell wall component

Which of the following is false in respect to cells' chromosomes?

Chromosomes only appear as a cell is about to divide.

Which statement about the cytoskeleton is true?

Components of the cytoskeleton often mediate the movement of organelles within the cytoplasm.

A shortage of phosphorus in the soil would make it especially difficult for a plant to manufacture __________.

DNA

In terms of cellular function, what is the most important difference between prokaryotic and eukaryotic cells?

Eukaryotic cells are compartmentalized, which allows for specialization.

The sex hormones estrogen, progesterone, and testosterone belong to which class of molecules?

Lipids

Enantiomers are

Mirror images

The endosymbiont theory explains the origins of __________.

Mitochodria and chloroplasts

Cilia and flagella move due to the interaction of the cytoskeleton with which of the following?

Motor proteins

Pharmaceutical companies are selling close to $200 billion worth of single-enantiomer drugs. Why might it be important to use only one form of an enantiomer?

One enantiomer may provide an effective treatment whereas the other may be ineffective or even toxic.

The tertiary structure of a protein includes all of the following interactions except _________ bonds.

Peptide

Which of the following is present in a prokaryotic cell?

Ribosomes

Which of the following groups is primarily involved in synthesizing molecules needed by the cell?

Ribosomes, rough endoplasmic reticulum, and smooth endoplasmic reticulum

Structural isomers have __________.

The same formula, but different covalent arrangements

__________ is always involved in hydrolysis reactions.

Water

The peptide bond is __________.

a covalent bond joining amino acids together to form a polypeptide

The extracellular matrix of the animal cell has all of the following molecular components except __________.

a middle lamella

Sickle-cell anemia is a disease that is caused by __________ in the __________ of the protein.

a single amino acid change; primary structure

In Miller's 1953 laboratory experiment, __________.

abiotic compounds cycled through the apparatus and were sampled for organic compounds

Choose the pair of terms that completes this sentence about functional groups in organic chemistry: Carboxyl is to __________ as __________ is to base.

acid; amino

Nitrogenous bases are classified as either purines or pyrimidines. Examples of purines are __________.

adenine and guanine; There are two families of nitrogenous bases: pyrimidines and purines. A pyrimidine has one six-membered ring of carbon and nitrogen atoms. The members of the pyrimidine family are cytosine (C), thymine (T), and uracil (U). Purines are larger, with a six-membered ring fused to a five-membered ring. The purines are adenine (A) and guanine (G). The specific pyrimidines and purines differ in the chemical groups attached to the rings. Adenine, guanine, and cytosine are found in both DNA and RNA; thymine is found only in DNA and uracil only in RNA.

Although the structures of the functional groups that are most important to life vary, they share one thing in common: They __________.

all are hydrophilic and increase the organic compound's water solubility

Which chemical group is most likely to be responsible for an organic molecule behaving as a base?

amino

Sugars have a(n) __________ group that interacts with a _________ group that forms ring structures when the dry molecule is placed in water.

carbonyl (-C=O); hydroxyl (-OH)

The organelle that is a plant cell's compartment for the storage of inorganic ions such as potassium and chloride is the __________.

central vacuole

Animal cells have unique organelles called __________ that are composed of structures called __________.

centrosomes; centrioles

The molecule with four fused rings that is found in animal membranes and is the precursor of vertebrate sex hormones is __________.

cholesterol

When comparing saturated and naturally occurring unsaturated fats, the unsaturated fats have __________ and are __________ at room temperature.

cis double bonds; liquids

When a double bond joins two carbon atoms, __________ can form.

cis-trans isomers

The type of bond that forms to join monomers (such as sugars and amino acids) into polymers (such as starch and proteins) is a(n) __________ bond.

covalent; Monomers are joined together by a dehydration reaction in which two molecules are covalently bonded to each other through the loss of a water molecule.

In living organisms, DNA exists as a __________ with the strand(s) __________.

double helix; running antiparallel

The subunits (monomers) in cellulose are linked together by __________.

glycosidic linkages

Observing a fluorescent micrograph cell with intermediate filaments would help you identify the cell as a __________.

human skin cell

The secondary structure of a peptide backbone is stabilized by __________ forming either a(n) __________ or a(n) __________.

hydrogen bonds; α helix; β pleated sheet

A protein that ultimately functions in the plasma membrane of a cell is most likely to have been synthesized __________.

in the rough endoplasmic reticulum

The walls of plant cells are largely composed of polysaccharides and proteins that are synthesized __________.

in the rough endoplasmic reticulum and in the Golgi apparatus

The proper three-dimensional shape and folding of a protein is assisted by _________.

molecules called chaperonins

Microfilaments function in cell motility including __________.

muscle contraction, amoeboid movement, and cytoplasmic streaming in plants

The endoplasmic reticulum is part of the endomembrane system, which also includes the __________.

nuclear envelope, the Golgi apparatus, lysosomes, and vesicles

The region of a bacterial cell that contains the genetic material is called the __________.

nucleoid

Inorganic carbon such as CO2 differs from organic carbon because __________.

organic carbon always has a hydrogen atom covalently attached to it

Dye injected into a plant cell might be able to enter an adjacent cell through __________.

plasmodesmata

Cell junctions in plant cells are called __________, and communicating junctions in animal cells are called __________.

plasmodesmata; gap junctions

The chemical group that helps stabilize protein structure is the __________.

sulfhydryl group (-SH)

Evidence that supports the prokaryotic origins of mitochondria and chloroplasts are all of the following except __________.

that mitochondria and chloroplasts have multiple copies of linear DNA molecules associated with their inner membranes

Triacylglycerol is a fat composed of...

three fatty acid molecules joined by ester linkages to one molecule of glycerol.

Biologically important chemical groups include all of the following except __________.

water (H2O)

Cell motility, which includes changes both in cell location and in the movement of cell parts, requires interactions of the cytoskeleton __________.

with motor proteins

Which type of protein shields a newly forming protein from cytoplasmic influences while it is folding into its functional form?

Chaperonins

The components of nucleic acids are __________.

a nitrogenous base, a pentose sugar, and a phosphate (NPP) (cold sugar tastes like phosphorus)

In the pharmaceutical industry, two enantiomers of a drug ...

may not be equally effective.

The chemical group that is involved in regulating DNA is the

methyl group (-CH3)

The carbon skeleton can vary in all of the following except __________.

lacking hydrogen atoms