Exam 2

Question 1

The ___ is a theory about plasma membrane structure that describes a bilayer in constant motion and membrane proteins arranged in an asymmetrical manner.

Answer 1

Fluid Mosaic Model

Question 2

Which of the following would not diffuse through the plasma membrane by means of simple diffusion?
A. a lipid soluble molecule
B. a small, noncharged molecule
C. glucose
D. water

Answer 2

C. glucose

Question 3

Which of the following is a function of a plasma membrane protein?
A. circulating antibody
B. forms a lipid bilayer
C. oxygen transport
D. molecular transport through the membrane

Answer 3

D. molecular transport through the membrane

Question 4

Solutions with a higher concentration of solutes than the concentration inside the cell are ___.

Answer 4

hypertonic

Question 5

What is the difference between active and passive transport across the plasma membrane?

Answer 5

Active transport is ATP dependent, whereas passive transport uses only the kinetic energy of the particles for movement across the plasma membrane.

Question 6

The lipid bilayer is composed of ___.

Answer 6

hydrophilic heads and hydrophobic tails

Question 7

The primary constituent of cell membranes are ___.

Answer 7

phospholipids

Question 8

The diffusion of water through a semipermeable membrane is called ___.

Answer 8

osmosis

Question 9

A red blood cell placed in pure water would ___.

Answer 9

swell and burst

Question 10

Which of the following describes the plasma membrane?
A. a double layer of protein enclosing the plasma
B. a single-layered membrane that surrounds the nucleus of the cell
C. a membrane composed of tiny shelves or cristae
D. the phospholipid bilayer surrounding the cell

Answer 10

D. the phospholipid bilayer surrounding the cell

Question 11

Larger molecules will diffuse ___ as compared to smaller molecules.

Answer 11

slower

Question 12

Catabolism...
A. drives anabolism
B. tends to be exergonic
C. breaks down molecules
D. supplies energy for endergonic reactions

Answer 12

C. breaks down molecules

Question 13

Energy of a moving object is also known as ___.

Answer 13

kinetic energy

Question 14

“Stored” or position energy is also known as ___.

Answer 14

potential energy

Question 15

Reactions that release energy are called ___.

Answer 15

exergonic

Question 16

The chemical reaction in which bonds are broken is usually associated with ___.

Answer 16

the release of energy

Question 17

The fact that the cell membrane allows some materials to pass while keeping others out is an example of ___.

Answer 17

selective permeability

Question 18

A difference in the number of molecules or ions in two associated areas is an example of a ___.

Answer 18

concentration gradient

Question 19

Diffusion will continue until ___ is achieved.

Answer 19

equilibrium

Question 20

A protein molecule that acts as a biological catalyst is called ___.

Answer 20

an enzyme

Question 21

The sum of all chemical reactions in the cell that build up and break down molecules is ___.

Answer 21

metabolism

Question 22

Which of the following is a concept of the cell theory?
A. only higher organisms are composed of cells
B. the subcellular organelle is the basic unit of life
C. a cell is the basic structural and functional unit of a living organism
D. simple cells can arise spontaneously from rotting vegetation

Answer 22

C. a cell is the basic structural and functional unit of a living organism

Question 23

Which of the following conditions would most likely DECREASE the rate at which a molecule will DIFFUSE across a cell membrane?
A. increase the permeability of the membrane to the molecule
B. decrease the molecular mass/weight of the molecule
C. decrease the number of channels for that particular molecule
D. increase the lipid solubility of the molecule

Answer 23

C. decrease the number of channels for that particular molecule

Question 24

This type of transport requires membrane protein yet no energy in the form of ATP.

Answer 24

facilitated diffusion

Question 25

The random movement of particles from an area of high concentration to an area of low concentration, which requires no energy in the form of ATP.

Answer 25

diffusion

Question 26

The inside of a cell contains 0.9% NaCl and the outside of the cell contains 0.9% NaCl. Which way will water diffuse?

Answer 26

Water will move equally in both directions.

Question 27

Which statement is true?
A. A cell placed in a hypotonic solution will shrink.
B. A cell placed in a hypertonic solution will swell.
C. A cell placed in a hypotonic solution will swell.
D. A cell placed in an isotonic solution will swell.

Answer 27

C. A cell placed in a hypotonic solution will swell.

Question 28

The diffusion of molecules across the plasma membrane would be affected by ___.

Answer 28

molecule size, temperature, and steepness of concentration gradient

Question 29

Which of the following contains more energy in the bonds of the molecule?
A. a micromolecule
B. the smaller amino acid subunits
C. a medium sized molecule
D. a large, complex molecule like a protein

Answer 29

D. a large, complex molecule like a protein

Question 30

Enzymes increase the rate of a given reaction by lowering what kind of energy?

Answer 30

activation energy

Question 31

When first focusing on an object under a microscope, which magnification should you use?

Answer 31

lowest (4x)

Question 32

How much are you magnifying something when you are using 10X oculars and the 4X objectives?

Answer 32

40x

Question 33

The only electrons that are important when considering bonding behavior are those in the ___ shell. This shell is called the ___ shell.

Answer 33

outermost, valence

Question 34

Which of the following is NOT true regarding atomic structure?
A. Electrons have a negative charge and are found outside of the nucleus.
B. Protons have a negative charge.
C. Neutrons have no charge.
D. Protons and neutrons are found in the nucleus of an atom.

Answer 34

B. Protons have a negative charge.

Question 35

What type of bond is formed whenever two atoms share a pair of electrons?

Answer 35

covalent

Question 36

Magnesium has 12 protons. How many electrons are in the second energy level?

Answer 36

8

Question 37

Which of the following is NOT true about matter?
A. Matter is anything that occupies space and has mass (weight).
B. Matter exists in solid, liquid, and gaseous states.
C. Liquids have neither a definite shape nor a definite volume.
D. Solids have a definite shape and volume.

Answer 37

C. Liquids have neither a definite shape nor a definite volume.

Question 38

A(n) ___ bond is a chemical bond between atoms formed by the transfer of one or more electrons from one atom to another.

Answer 38

ionic

Question 39

A(n) ___ bond is a chemical bond in which electrons are shared which produced molecules in which the shared electrons occupy a single orbital common to both atoms.

Answer 39

covalent

Question 40

A(n) ___ bond is a unique chemical bond where a hydrogen atom is attracted by another electron-hungry atom.

Answer 40

hydrogen

Question 41

Amino acids are linked together by ___ bonds.

Answer 41

peptide

Question 42

Which is the “building block” of carbohydrates?

Answer 42

monosaccharides

Question 43

Name the molecules unique to living systems that all contain carbon (aka name the 4 organic compounds) and state the basic function of each of the 4 organic compounds.

Answer 43

The molecules unique to all living systems that contain carbon are carbohydrates, lipids, proteins, and nucleic acids. Each of these organic compounds have basic functions. Carbohydrates are used for energy storage and structural support. Lipids are used for long term energy storage. Proteins are extremely useful to us in the form of enzymes, hormones, and structural requirements such as bones. Finally, nucleic acids carry genetic information. Without each of these organic compounds, carbon based living systems would not be able to survive efficiently.

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Question 44

The plasma membrane separates two of the body’s major fluid compartments, the ___ fluid within the cells and the ___ fluid outside the cells.

Answer 44

intra(cellular),

extra(cellular)

Question 45

___ is the tendency of molecules or ions to move from an area where they are in higher concentration to an area where they are in lower concentration or down their concentration gradient.

Answer 45

Diffusion

Question 46

A physiologist observes that the concentration of sodium inside a cell is decidedly lower than that outside the cell. Sodium diffuses easily across the plasma membrane of such cells when they are dead, but not when they are alive. What cellular function that is lacking in dead cells explains the difference?

Answer 46

active transport (solute pumping)

Question 47

Osmosis always involves ___.

Answer 47

a selectively permeable membrane, diffusion, and a difference in solvent concentration

Question 48

Describe the similarities and differences in simple diffusion and general facilitated diffusion.

Answer 48

Simple diffusion and facilitated diffusion have many similarities and differences. Both types of diffusion do not require energy, or ATP, to be completed. However, facilitated diffusion uses a channel protein which allows for passage of a higher range of molecules. Simple diffusion is done across the cell’s semipermeable membrane which is more selective in which molecules may enter or exit the cell.

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Question 49

Compare and contrast passive membrane transport and active membrane transport.

Answer 49

Passive and active membrane transport both allow molecules to diffuse across the cell’s membrane. However, passive membrane transport does not require any energy, or ATP, to be completed. Active membrane transport on the other hand does require ATP. Due to to use of ATP in active membrane transport, a greater multitude of molecules are allowed to cross over the cell membrane.

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Question 50

(T/F) Tonicity refers to the tone of a muscle after exercise.

Answer 50

false

Question 51

(T/F) Ions diffuse according to electrochemical gradients, recognizing the effect of both electrical and concentration (chemical) forces.

Answer 51

true

Question 52

(T/F) Endocytosis, phagocytosis, and pinocytosis are all methods of passive transport.

Answer 52

false

Question 53

Briefly share the differences in endocytosis and exocytosis.

Answer 53

In endocytosis materials are taken into the cell by pinching off the plasma membrane to form a vesicle. Exocytosis on the other hand assists materials in exiting the cell by allowing the vesicle, formed inside the cell, to refuse with the plasma membrane.

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Question 54

Describe the differences between organic and inorganic compounds. Provide examples of each and explain the basic importance/need of those in the human body.

Answer 54

An organic molecule is any covalent molecule with both a Carbon and Hydrogen. They function as an energy source, structural material, and carry hereditary information. Inorganic molecules include water, salts, acids and bases. Water makes up about 70% of living cells’ volume. Acids and bases play a huge role in our environment as well as our bodies. Buffers in our bodies are teams of acids and bases that work together to bring cells to a normal pH and therefore maintain homeostasis.

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Question 55

(T/F) Enzymes are globular proteins that act as biological catalysts that slow or decelerate the rate of biochemical reactions.

Answer 55

false