普通生物學一上109期中考古題

40問 • 2年前

問題一覧

In the formation of biofilms, such as those forming on unbrushed teeth, cell signaling serves which function?

secretion of substances that inhibit foreign

When a neuron responds to a particular neurotransmitter by opening gated ion channels, the neurotransmitter is serving as which part of the signal pathway?

signal molecule

What does it mean to say that a signal is transduced?

The physical form of the signal changes from one form to another

In signal transduction, phosphaeases

move the phosphate group of the transduction pathway to the next molecule of a series

If a pharmaceutical company wished to design a drug to maintain low blood sugar levels, one approach might be to design a compound .

（D）that increases phosphodiesterase activity

Sutherland discovered that the signaling molecule epinephrine

（D）elevates cytosolic concentrations of cyclic AMP

An animal cell lacking oligosaccharides on the external surface of its plasma membrane would likely be impaired in which function?

cell-cell recognition

For a protein to be an integral membrane protein, it would be

amphipathic, with at least one hydrophobic region

In what way do the membranes of a eukaryotic cell vary?

（B）Certain proteins are unique to each membrane

Which of the following is a characteristic feature of a carrier protein in a plasma membrane?

It exhibits a specificity for a particular type of molecule

The voltage across a membrane is called the

membrane potential

The force driving simple diffusion is____ , while the energy source for active transport is_____ .

the concentration gradient; ATP

All of the following are part of a prokaryotic cell EXCEPT

an endoplasmic reticulum

In bacterium, we will find DNA in

the nucleoid

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

mRNA

A cell with an extensive area of smooth endoplasmic reticulum is specialized to

（B）synthesize large quantity of lipids

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

Golgi apparatus

Motor proteins provide for molecular motion in cells by interacting with what types of cellular structures

compoents of the cytoskeleton

Which of these classes of biological molecules does NOT include polymers?

lipids

What is the difference between an aldose sugar and a ketose sugar?

the position of the carbonyl group

What does the term insoluble fiber refer to on food packages?

cellulose

Phospholipid and triglycerides both

have a glycerol backbone

Which one of the following is NOT a component of each monomer used to make proteins?

a phosphorus atom, P

Why do neurons and some other specialized cells divide infrequently?

They have entered into G0

Which of the following molecules is released by platelets in the vicinity of an injury?

PDHF

Which of the following properties is associated with a cyclin-dependent kinase (Cdk)?

A Cdk is an enzyme that attaches phosphate groups to other proteins

The M phase checkpoint ensures that all chromosomes are attached to the mitotic spindle. If this does not happen, cells would most likely be arrested in

metaphase

Taxol is an anticanaer drug extracted from the Pacific yew tree. In animal cells, Taxol prevents microtubule deploymerization. Thus, haxol stops mitosis by interfering with which of the following structures or processes?

the mitotic spindle

Which of the following events occurs during interphase of the cell cycle?

replication of the DNA

In a chemical reaction,

transition state species have higher free energy than either reactants or the products

Trypsin and elastase are both enzymes that catalyze hydrolysis of peptide bonds. But trypsin only cuts next to lysine and elastase only cuts next to alanine. Why?

The shape of the active site for the two enzyme is different

Which statement about enzymes is true?

（D）Enzymes speed up reactions by lowering the activation energy

Nerve gases such as Sarin and malathion

bond covalently to the active site of the enzyme

A sigmoid curve in the graph of reaction rate – substrate concentration is typical for

an enzyme with multiple subunits, an active site

In a metabolic pathway, buildup of the end product usually

allosterically inhibits the enzyme catalyzing the commitment step

Which statement about oxidative phosphorylation is NOT true

It takes place in the matrix of mitochondria

Which statement is true?

methane has higher free energy than methanol

the end products of glycolysis of 1 molecule of glucose include: a. CO2 b. NADH c. ATP d. pyeuvate e. FADH2

2b, 2c, 2d

In eukaryotic cells, the citric acid cycle

is positively regulated by ADP or NAD+

In lactate fermentation,

NAD+ is regenerated

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楊雅筑 · 100問 · 2年前