exam 2

Question 1

What kind of bond holds the atoms of a single water molecule together?

Answer 1

covalent bonds that are polar

Question 2

Imagine a balloon is made from a membrane that’s permeable to water but not sucrose molecules. If the balloon is filled with a 50% sucrose solution and then placed in a beaker of water, how will the concentration of sucrose change inside the balloon (if at all

Answer 2

It will become less concentrated.

Question 3

Which food is most likely to contain all essential amino acids?

Answer 3

beef

Question 4

Imagine a newly discovered biological molecule that is mostly hydrophobic in its structure. This new molecule will most likely be classified as a

Answer 4

lipid

Question 5

Which of the following is a hormone that is involved in digestion?

Answer 5

gastrin

Question 6

Which of the following is considered part of a life-form’s metabolism?

Answer 6

secretion of wastes

Question 7

Which of the following is a lipid?

Answer 7

cholesterol

Question 8

Table sugar (sucrose) belongs to which category of nutrients?

Answer 8

carbohydrates

Question 9

Enzymes are

Answer 9

proteins

Question 10

Which of the following is an example of a food that is rich in complex carbohydrates?

Answer 10

pasta

Question 11

What kind of molecule forms a bilayer that is the basis for all cellular membranes?

Answer 11

phospholipid

Question 12

What part of the digestive system has the most surface area for the absorption of nutrients

Answer 12

small intestine

Question 13

Just before entering the small intestine, what is the pH of chyme?

Answer 13

acidic (low pH)

Question 14

What does hydrophobic mean?

Answer 14

repelled by water

Question 15

Which of the following best describes the structure of the plasma membrane?

Answer 15

a double layer of lipids with proteins embedded in it

Question 16

Sodium chloride is composed of molecules that are stable when dry. In the presence of water, however, the atoms that compose the molecules separate from each other. What type of chemical bond holds the dry substance together?

Answer 16

ionic bonds

Question 17

Because the electrons in a water molecule are shared unequally between hydrogen and oxygen, water is said to be

Answer 17

polar

Question 18

Which macronutrient is the major source of energy for cell processes?

Answer 18

carbohydrates

Question 19

Imagine a balloon is made from a membrane that’s permeable to water but not sucrose molecules. If the balloon is filled with a 50% sucrose solution and then placed in a beaker of water, then the balloon will

Answer 19

gets larger as it gains water

Question 20

What type of chemical bond connects the complementary strands of a DNA molecule to each other?

Answer 20

hydrogen bonds

Question 21

A person can live a normal life without which of these digestive system organs?

Answer 21

gallblader

Question 22

What are the monomer “building blocks” that make up proteins?

Answer 22

amino acids

Question 23

Which macromolecule has a sugar-phosphate backbone?

Answer 23

nucleic acid

Question 24

Which of the following pairs of molecules can be held together by a hydrogen bond?

Answer 24

two polar molecules

Question 25

Why are whole foods better for your health than processed foods?

Answer 25

Processed foods don't contain all the vitamins and minerals found in whole foods

Question 26

Oxygen in highly electronegative, meaning that it

Answer 26

pulls electrons toward itself.

Question 27

A person born without an epiglottis couldn't

Answer 27

swallow food without a high risk of choking.

Question 28

Which organelle contains digestive enzymes that degrade a variety of macromolecules?

Answer 28

lysosome

Question 29

Which organelle performs cellular respiration?

Answer 29

mitochondrion

Question 30

Polysaccharides are polymers of

Answer 30

sugars

Question 31

What is the correct sequence of bodily organization, from simple to complex?

Answer 31

cells - tissues - organs - organ systems - organism

Question 32

Nonliving things include fire, water, and viruses. Many features of living things are also found in nonliving things. Of the following features, which is most likely to be absent in nonliving things?

Answer 32

homeostasis

Question 33

If life on Mars is fundamentally like life on Earth, its macromolecules will be based on which element?

Answer 33

carbon

Question 34

How do the concentrations of H+ and OH- compare to each other in an acidic solution?

Answer 34

The concentration of H+ is higher.

Question 35

The plasma membrane of a photosynthetic eukaryotic cell

Answer 35

isolates the cell's contents from the external environment.

Question 36

When molecules or atoms move down a concentration gradient across cell membranes, it's called

Answer 36

passive transport.

Question 37

Proteins are polymers of

Answer 37

amino acids

Question 38

Erin wants to make a stir fry using an unsaturated fat. Sam suggests that she use

Answer 38

olive oils

Question 39

Monosaccharides can be used by body cells

Answer 39

for energy production

Question 40

Diffusion is

Answer 40

the movement of molecules from an area of high concentration to an area of low concentration

Question 41

Nucleic acids are polymers of

Answer 41

nucleotides.

Question 42

Which of the following could accept one (and only one) electron?

Answer 42

hydrogen (atomic number = 1)

Question 43

Why is fiber an important part of a healthful human diet?

Answer 43

It may decrease the risk of certain types of cancers.

Question 44

A digested nutrient enters the bloodstream via

Answer 44

tiny blood vessels inside the microvilli.

Question 45

A solution with a pH of 2 has an H+ ion concentration that is ________ than a solution with a pH of 4.

Answer 45

100 times higher

Question 46

What is a major difference between saturated and unsaturated fats?

Answer 46

Unsaturated fats contain carbon-to-carbon double bonds, but saturated fats don't.

Question 47

Which of the following is NOT a macronutrient?

Answer 47

vitamin C

Question 48

Microtubules, microfilaments, and intermediate filaments compose what part of a cell?

Answer 48

cytoskeletal elements

Question 49

The atomic number of an element refers to the number of ________ in one atom of that element

Answer 49

protons

Question 50

Octet Rule

Answer 50

atoms are in their most stable configuration when the outermost shell holds exactly 8 electrons