BSC1010 Exam 2

Which molecule is an example of a polysaccharide

Starch

A fat that is completed hydrogenated would be

saturated and solid at room temperature

DNA Nucleotides include

thymine, guanine, adenine, and cytosine

Carbohydrates typically include

C, H, and O atoms

A DNA molecule has the sequence TCAACTTGA. The equivalent RNA molecule would have the sequence

AGUUGAACU

Which statement is TRUE with regard to a DNA molecule?

The amount of adenine is equal to the amount of thymine, and the amount of guanine is equal to the amount of cytosine.

Which substance is hydrophilic

Cellulose

A protein's function is dependent on environmental factors such as pH and temperature. What property of the protein itself dictates a protein's function?

Shape

A specific stretch of DNA that contains information for the amino acid sequence of a polypeptide is a(n)

Gene

Amino acids include a side group as well as

a central carbon, a hydrogen atom, an amino group, and a carboxyl group

Which of the following organelles produces and modifies polysaccharides that will be secreted?

Golgi apparatus

John would like to film the movement of chromosomes during cell division. His best choice for a microscope would be a (an)

Light microscope

Which of the following statements best explains how a modern transmissien electren microscope (TEM) can achieve a resolution of about 2.0 nanometers, whereas a standard light mierescope has a maximum resolution of about 200 nanometers?

The wavelengths of electron beams are much shorter than the wavelengths ef visibie light

Which of the following macromolecules leave the nucleus of a eukaryotic cell through pores in the nuclear membrane?

mRNA

Which of the following statements describes a major advantage of light microscopy over electren microscopy?

light microscopy allows the visualization of dynamic processes in living cells

In the bacteria DNA will be found in

the nucleoid

Examination of a cell by transmission electron microscopy reveals a high density of ribosomes in the cytoplasm.

This observation suggests that this cell is actively producing large amounts of which of the following molecules?

Proteins

Which structure below is independent of the endomembrane system?

Chloroplast

A cell with a predominance of rough endoplasmic reticulum is most likely

producing large quantities of proteins for secretion

A cell with a predominance of smooth endoplasmic reticulum is likely specialized to

synthesize large quantities of lipids

Cilia and flagella bend because of

a motor protein called dynein

Which domains of life are classified as prokaryotes?

Bacteria and Archaea

A (An) _ is the type of microscope useful for exploring the ultrafine internal structure of a cell

transmission electron microscope (TEM)

is the ability of a microscope to show two objects as separate.

Resolving power

Which structure is common to plant and animal cells?

mitochondrion

Thylakoids, DNA, and ribosomes are all components found in

Chloroplasts

A newly discovered unicellular organism isolated from acidic mine drainage is found to contain a cell wall, a plasma membrane, twe flagella, and peroxisomes. Based just on this information, the organism is most likely

A motile eukaryote

Which of the following frequently imposes a limit on cell size?

ratios of surface area to volume

What is the function of the nuclear pore complex found in eukaryotes?

it regulates the movement of preteins and RNAs into and out of the nucleus

Which of the following is a major difference between prokaryotic cells and eukaryotic cells?

Eukaryotic cells have membrane bound organelles while prokaryotic cells do not

Which of the following factors would tend to increase membrane fluidity?

a greater proportion of unsaturated phospholipids

How are the tails and heads of membrane phospholipids oriented in their environment?

The hydrophobic tails are oriented towards each other and the hydrophillic heads are oriented towards the extracellular fluid and the intracellular fluid.

A type of transport of a solute across a membrane, up its concentration gradient, using protein carriers driven by the expenditure of chemical energy is known as

active transplant

Which of the following processes includes all the others?

Passive transport

What is the main component of an animal cell membrane?

Phospholipids

Which type of proteins is embedded in the cell membrane in both active transport and facilitated transport

Carrier

The activation of receptor tyrosine kinases is characterized by

dimerization and phosphorylation

Vasopressin is a hormone that is primarily released when the body is low on water. Release of vasopressin causes the kidneys to conserve water by concentrating urine and decreasing urine output. However, vasopressin also has additional functions in other tissues such as the brain and blood vessels, which are not directly involved in urine production. How could it be possible for vasopressin to trigger different responses in different tissues?

Vasopressin can bind to, and act on, different receptor subtypes, leading to different cellular responses in different tissues.

What property defines most ligands for intracellular receptors?

They are lipid-soluble

A small number of cell surface receptors can ultimately generate a large intracellular response due to activation of kinase cascades. This is referred to as:

signal amplification.

Lipid-soluble signaling molecules, such as aldosterone, cross the membranes of all cells but affect only target cells because

intracellular receptors are present only in target cells

Protein phosphorylation is commonly involved with which of the following?

activation of protein kinase molecules