Biology Test 2 clicker questions and important terms

In order to start an exergonic reaction, a certain amount of energy must be absorbed by the reactants. This is called the energy of activation. Which of the following represents the energy of activation without enzymes?

a

Membranes organize cell activities. The proteins embedded in the membranes are essential to their function. These membrane proteins have properties that allow them to "float" in the membrane. Which of the following statements describes those properties? a)The surface region of the protein in the interior of the membrane is mostly hydrophobic. b)The surface region of the protein in the interior of the membrane is mostly hydrophillic. c)The surface region of the protein exposed to the outer environment is hydrophobic. d)The surface region of the protein exposed to the outer environment is hydrophilic.

a)The surface region of the protein in the interior of the membrane is mostly hydrophobic.

Which of the following represents the energy of activation as modified by an enzyme?

b

Cells are small, but molecules are even smaller. Compared to a water molecule, about how many times larger is a typical animal or plant cell (about 100 µm in diameter)? a)A typical cell is 1 million times larger(diameter) than a water molecule. b)A typical cell is 100,000 times larger (diameter) than a water molecule. c)A typical cell is 10,000 times larger (diameter) than a water molecule. A typical cell is 1,000 times larger (diameter) than a water molecule

b)A typical cell is 100,000 times larger (diameter) than a water molecule.

The figure represents an overview of the entry pathways to cellular respiration when different macromolecules are digested for energy production. Why are none of the digestive products entering the electron transport chain directly? a)The electron transport chain is too deeply embedded in the mitochondria. b)The electron transport chain only receives electrons carried by reduced electron carrier molecules such as NADH. c)The electron transport chain only receives electrons carried by oxidized electron carrier molecules such as NAD+. d)The electron transport chain does not produce ATP.

b)The electron transport chain only receives electrons carried by reduced electron carrier molecules such as NADH.

Enzymes catalyze the many reactions in a cell. There are hundreds of different enzymes in a cell—each with a unique three-dimensional shape. Why do cells have so many different enzymes? a)Each enzyme molecule can only be used once. b)The shape of an enzyme's active site generally fits a specific substrate. c)The substrate molecules react with enzymes to create new enzymes. d)Enzymes are randomly produced. With thousands of different shapes, one is likely to work.

b)The shape of an enzyme's active site generally fits a specific substrate. The substrate molecules

This graph illustrates how an enzyme catalyzes a reaction in a biological system. From an energy standpoint, is this reaction endergonic or exergonic? a)endergonic b)exergonic c)There is not enough information in the graph to determine the type of reaction.

b)exergonic

Plant cells have a cell wall to maintain cell shape and to give the plant structure. Animal cells lack a cell wall but still maintain an overall shape within tissues. Which of the following is/are responsible for this phenomenon? a)microtubules b)extracellular matrix c)tight junctions d)anchoring junctions

b)extracellular matrix b)tight junctions

The figure represents an overview of the processes of cellular respiration. Which of the following correctly identifies the processes in the correct order? a)glycolysis, electron transport chain, citric acid cycle b)glycolysis, citric acid cycle, electron transport chain c)citric acid cycle, electron transport chain, glycolysis d)electron transport chain, glycolysis, citric acid cycle

b)glycolysis, citric acid cycle, electron transport chain citric acid cycle, electron

The primary function of microtubules inside a cell is a)maintaining the cell's shape. b)movement, as a track along which proteins and organelles can move. c)movement, in the contraction of the muscle cells.

b)movement, as a track along which proteins and organelles can move.

This diagram represents osmosis of water across a semipermeable membrane. What could you do to level the solutions in the two sides of the U-tube on the right? a)Add more water to the left-hand side. b)Add more water to the right-hand side. c)Add more solute to the left-hand side. d)Add more solute to the right-hand side.

c)Add more solute to the left-hand side.

The three domains of life described by biologists today are the bacteria, archaea, and eukarya (all other forms of life). What is the basic difference between eukaryotes and prokaryotes (archaea and bacteria)? a)Prokaryotes do not have a plasma membrane surrounding the cell. b)Prokaryotes use RNA and not DNA to pass on the genetic message. c)The interior of the cell of eukaryotes is divided by internal membranes into specialized compartments. d)Eukaryotes engage in cellular metabolism; prokaryotes do not.

c)The interior of the cell of eukaryotes is divided by internal membranes into specialized compartments.

The scale of life at the cellular level can be difficult to understand. The scale on this chart is logarithmic: Each line represents a factor of 10. Compared to a typical animal or plant cell (about 100 µm in diameter), how much smaller is a mitochondrion? a)Mitochondria and animal cells are essentially the same size. b)The length of a mitochondrion is about 1/10th the diameter of an animal cell. c)The length of a mitochondrion is about 1/100th the diameter of an animal cell. d)The length of a mitochondrion is about 1/1,000th the diameter of an animal cell.

c)The length of a mitochondrion is about 1/100th the diameter of an animal cell.

A protein that is bound for secretion from a cell is produced by a)ribosomes floating free in the cytoplasm. b)ribosomes within the Golgi apparatus. c)ribosomes found on the rough endoplasmic reticulum. d)ribosomes found on the smooth endoplasmic reticulum.

c)ribosomes found on the rough endoplasmic reticulum.

Some prokaryotic and all eukaryotic cells use oxygen to harvest energy from food molecules. In what form is that energy available to power cellular work? a)heat and light b)glucose molecules c)fat molecules ATP molecules

d)ATP molecules

The cell is sometimes described as a protein factory. Using the cell-as-factory analogy, which of the following accurately describes the functions of the endomembrane system? a)The ribosomes on the roughendoplasmic reticulum areanalogous to a productionline in a factory. b)The Golgi apparatus isanalogous to the packagingand shipping department. c)The nucleus is analogous to management offices. all of the above

d)all of the above

Images generated by the Hubble Space Telescope give us a very limited view of the universe. Likewise, the clarity of the image of cells under a light microscope is limited by the microscope's ability to resolve cellular parts. Which of the following cell parts are visible with a light microscope? a)ribosomes b)large macromolecules c)microtubules d)mitochondria—just barely

d)mitochondria—just barely

Fat molecules store 9 kcal/g. There are about 454 g in a pound of fat, so one pound of fat stores about 4,000 kcal of energy. Based on the chart of energy consumption, which of the following would "burn off" a pound of fat? a)running 7 miles b)swimming 2 miles c)walking 27 miles(3 miles per hour) running 40 miles

d)running 40 miles