Biology 1001 Exam 2 (LSU-Hrincevich)

CHAPTER 5: Within the fluid mosaic of a plasma membrane, what is the role of transport and channel proteins?

They permit salts and sugars to move through the plasma membrane.

CHAPTER 5: If red blood cells are taken from the body and placed in a hypertonic solution, what happens to the cells?

The cells shrivel up because water leaves them.

CHAPTER 5: Plasma membranes are BEST described as a what?

single layer of phospholipids with tails pointed toward the inside of the cell.

CHAPTER 5: Osmosis moves water from a region of what to what?

low concentration of dissolved material to a region of high concentration.

CHAPTER 5: More than half a century ago, two cell biologists published details of their research involving isolated membrane vesicles from chloroplasts. Normally, the fluid inside these vesicles is near neutral. In an experiment, these membrane vesicles were soaked in an acidic solution (pH 4) until the inside of the vesicle also became pH 4. Based on the details provided in this scenario, by what mechanism could hydrogen ions have crossed the vesicle membrane, and what do you think happened at the molecular level?

Facilitated diffusion; hydrogen ions moved into the vesicle through a channel.

CHAPTER 5: Suppose that plasma membranes were single layers of phospholipids with heads facing the external environment. The interior of this hypothetical cell would have to be what?

hydrophobic and nonpolar.

CHAPTER 5: The cytoplasm of a certain cell, such as a neuron, already has a high concentration of potassium ions. How can potassium ions continue to enter the cell?

active transport

CHAPTER 5: The blood plasma of a man who drinks saltwater will become ________ to his red blood cells, whereas the red blood cells will be ________ to the blood plasma. Which statement below correctly completes the statement?

hypertonic; hypotonic

CHAPTER 5: Which of the following types of membrane proteins are responsible for conveying external messages such as those sent by a hormone signal?

receptor proteins

CHAPTER 5: The hydrophobic tails of a phospholipid bilayer are oriented toward the what?

interior of the plasma membrane (i.e., toward one another).

CHAPTER 6: The optimum reaction rate of a particular enzyme occurs at pH 7.3 at 37 degrees C. This reaction would probably proceed faster by doing what?

increasing the temperature to 38 degrees C and keeping the pH at 7.3.

CHAPTER 6: Similar to a car, a human body is approximately how efficient in converting chemical energy to movement?

25%

CHAPTER 6: All of the following statements pertaining to catalysts are true EXCEPT which one?

catalysts increase activation energy requirements.

CHAPTER 6: Imagine you are conducting an experiment on an enzyme known as sucrase. This enzyme is synthesized and used by yeast cells to break down the disaccharide sucrose (table sugar) into the monosaccharides glucose and fructose. You decide to conduct an experiment to test whether the sucrase enzyme can break down the artificial sweetener sucralose. Sucralose (a "chlorinated" carbohydrate) has some chemical similarity to sucrose, but is different in that three of its hydroxyl groups are missing and replaced with chlorine atoms instead. Based on the details provided in this scenario, do you think the sucrase enzyme will be able to interact with sucralose?

No; all enzymes are highly specific and can react with only a specific substrate.

CHAPTER 6: In cells, endergonic reactions are often coupled with enzymatic reactions that store energy. True or False?

FALSE

CHAPTER 6: When a high-energy bond of ATP is broken, primarily what happens to the released energy?

It drives endergonic reactions in the cell.

CHAPTER 6: Which of the following does not have much potential energy?

a ball that has rolled downhill and stopped

CHAPTER 6: Imagine you are conducting an experiment on a yeast enzyme known as sucrase. This enzyme is used by yeast cells to break down sucrose into glucose and fructose. What type of reaction is this?

exergonic

CHAPTER 6: Entropy is a measure of an increase in what?

randomness.

CHAPTER 6: In the liver, the polysaccharide glycogen is broken down into glucose monomers. The glucose molecules are then released into the blood when blood sugar levels need to be raised. This process is an example of what type of reaction?

exergonic

CHAPTER 7: The energy of the movement of electrons down a concentration gradient via electron transport within chloroplasts and mitochondria is used to generate molecules of:

ATP.

CHAPTER 7: Where is glucose synthesized during photosynthesis?

cytoplasm

CHAPTER 7: Albino corn has no chlorophyll. You would expect albino corn seedlings to:

fail to thrive because they cannot capture light energy.

CHAPTER 7: Hydrogen ions cross the thylakoid membranes from the stroma by:

active transport.

CHAPTER 7: Which process of photosynthesis is linked to the production of ATP?

photosystem II

CHAPTER 7: C3 plants are adapted to ________ environmental conditions, whereas C4 plants are adapted to ________ conditions.

wet; dry

CHAPTER 7: During the process of photosynthesis, solar energy is converted to:

chemical energy.

CHAPTER 7: Which of the following provides oxygen as an end product?

light reaction

CHAPTER 7: The primary function of the light reactions of photosynthesis is to:

produce energy-rich ATP and NADPH.

CHAPTER 7: The energy source in photosynthesis is:

visible light.

CHAPTER 8: If no oxygen is available to a cell, then the net ATP production resulting from the metabolism of a single glucose molecule is what?

two ATP molecules.

CHAPTER 8: Chemiosmosis links a hydrogen ion gradient to the production of ATP. True or False?

TRUE

CHAPTER 8: The term "chemiosmosis" is associated with which process?

the electron transport chain

CHAPTER 8: When oxygen is present, what happens?

most animal cells utilize aerobic cellular respiration.

CHAPTER 8: Products of the fermentation process include all of the following EXCEPT what?

pyruvate.

CHAPTER 8: During glycolysis, "glucose activation" refers to the what?

use of two ATP molecules to make one fructose bisphosphate molecule.

CHAPTER 8: The step in aerobic respiration that produces the most ATP per molecule of glucose is what?

chemiosmosis.

CHAPTER 8: At the end of glycolysis, the original carbons of the glucose molecule form what?

two molecules of pyruvate.

CHAPTER 8: Which of the following processes occurs in a membrane?

the electron transport chain

CHAPTER 8: Carbon dioxide is considered a waste product of cellular respiration. True or False?

TRUE