BIO 120 Test 3

Which of the following statements best describes metabolism in \n its entirety in all organisms?

Metabolism consists of all the energy transformation reactions \n in an organism.

Which of the following statements best describes the first law of \n thermodynamics?

Energy cannot be created or destroyed.

Which of the following statements best describes a primary \n mechanism by which the energy released in ATP hydrolysis is \n used directly to drive endergonic chemical reactions in a cell?

The released phosphate is used to form phosphorylated \n intermediates that are more reactive than the original \n phosphorylated substrate.

What is the main carrier of energy for metabolic work in cells?

ATP

Crossing over of chromosomes normally takes place during which of the \n following processes?

Meiosis I

A particular organism has 46 chromosomes in its karyotype. \n Which of the following statements is correct regarding this \n organism?

It produces gametes with 23 chromosomes

Which diagram represents anaphase I of meiosis?

I

In addition to activating or inhibiting enzymes through allosteric \n regulation, which of these mechanisms do cells also use to \n control enzymatic activity?

localization of enzymes into specific organelles or membranes

Many diploid organisms produce haploid gametes for \n reproduction. Which of the following best describes how the \n diploid number of chromosomes is restored in the offspring of \n these organisms?

fertilization combines chromosomes from each parent into \n resulting zygote

Disruption of the active site of an enzyme would most likely result in which \n of the following?

A decreased ability of the enzyme to bind substrates.

Energy of activation can be decreased by?

Enzymes

Which of the following processes occur during meiosis but not \n mitosis?

Diploid cells form haploid cells.

Which of the below are differences between meiosis I and \n meiosis II?

Meiosis I increases genetic variability while meiosis II creates \n haploid cells.

What number and types of chromosomes are found in a human somatic cell?

44 chromosomes & 2 sex chromosomes

Which of the following would be unlikely to contribute to the substrate specificity of an enzyme?

the enzyme has an allosteric regulatory site

Which statement about the binding of enzymes and substrates is correct?

when substrate molecules bind to the active site of the enzyme, the enzyme undergoes a slight change in shape

Which of the following is NOT a way in which an enzyme can speed up the reaction that it catalyzes?

The active site can provide heat from the environment that raises the energy content of the substrate

Which of the following statements about the role of ATP in cell metabolism is true?

The energy from the hydrolysis of ATP may be directly coupled to endergonic processes by the transfer of the phosphate group to another molecule

Catabolic Pathways:

release energy by breaking down complex molecules into simpler compounds

Anabolic pathways:

consume energy to build complex molecules from simpler ones

What is Gibbs Free energy?

the portion of a system’s energy that can do work when temperature and pressure are uniform throughout the system, as in a living cell

Exergonic reaction

“energy outward” // proceeds with a net release of free energy to the surroundings

Endergonic reaction

“energy inward” // absorbs free energy from the surroundings

What is an allosteric regulation

occurs when a regulatory molecule binds to a protein at one site and affects the protein’s function at another site