Period 1 Interactions

Question 1

Recall from our sugar dissolving lab that water with higher thermal energy (temperature) dissolves sugar faster. Why is this?

A) Because the water molecules are moving faster and can more quickly mix with the sugar molecules.

B) Because the water molecules are moving slowly and can more quickly mix with the sugar molecules.

C) Because the water molecules are moving faster and can more slowly mix with the sugar molecules.

D) Because the water molecules are moving slowly and can more slowly mix with the sugar molecules.

Answer 1

A) Because the water molecules are moving faster and can more quickly mix with the sugar molecules.

Recall from our sugar dissolving lab that water with higher thermal energy (temperature) dissolves sugar faster. This is because the water molecules are moving faster and can more quickly mix with the sugar molecules.

Question 2

Fill in the blank:

When substances dissolve, they mix evenly with each other and form a _____________ mixture.

Answer 2

homogeneous

When substances dissolve, they mix evenly with each other and form a homogeneous mixture.

Question 3

Fill in the blank:

Substances that do not mix evenly and separate into layers are called ___________ mixtures.

Answer 3

heterogeneous

Substances that do not mix evenly and separate into layers are called heterogeneous mixtures.

Question 4

True or false:

When mixtures settle (either evenly or in layers) the potential energy of the interacting molecules lowers

Answer 4

TRUE! You donkey

When mixtures settle (either evenly or in layers) the potential energy of the interacting molecules lowers.

Question 5

Fill in the blank:

________ molecules have permanent slight positive and negative charges.

Answer 5

Polar molecules have permanent slight positive and negative charges.

Question 6

Fill in the blank:

________ molecules have no permanent charges.

Answer 6

Nonpolar molecules have no permanent charges.

Question 7

True or false:

Nonpolar molecules have strong attractions to each other due to their charges.

Answer 7

FALSE! Polar molecules have strong attractions to each other due to their charges.

Question 8

Nonpolar molecules have a weak attraction to other nonpolar molecules. Why is this?

A) In nonpolar molecules, electron movements cause temporary charges to develop. The charges quickly disappear. The result of this is a weak attraction to other nonpolar molecules.

B) In nonpolar molecules, electron movements cause permanent charges to develop. The charges quickly disappear. The result of this is a weak attraction to other nonpolar molecules.

C) In nonpolar molecules, electron movements cause temporary charges to develop. The charges quickly re-appear. The result of this is a weak attraction to other nonpolar molecules.

Answer 8

A) In nonpolar molecules, electron movements cause temporary charges to develop. The charges quickly disappear. The result of this is a weak attraction to other nonpolar molecules.

Question 9

When polar and nonpolar molecules are mixed, they separate into different layers. This is because:

A) the polar molecules are more attracted to themselves than the nonpolar molecules.

B) the polar molecules are less attracted to themselves than the nonpolar molecules.

C) the nonpolar molecules are less attracted to themselves than the nonpolar molecules.

D) the nonpolar molecules are more attracted to themselves than the nonpolar molecules.

Answer 9

A) the polar molecules are more attracted to themselves than the nonpolar molecules.

When polar and nonpolar molecules are mixed, they separate into different layers. This is because the polar molecules are more attracted to themselves than the nonpolar molecules.

Question 10

True or false:

A polar substance like water and a nonpolar substance like oil cannot mix evenly because as the polar water molecules attract and move towards each other, they push away the nonpolar oil molecules.

Answer 10

TRUE!

A polar substance like water and a nonpolar substance like oil cannot mix evenly because as the polar water molecules attract and move towards each other, they push away the nonpolar oil molecules.

Question 11

True or false:

Substances will only mix evenly if they are both polar or nonpolar.

Answer 11

TRUE!

Substances will only mix evenly if they are both polar or nonpolar.

Question 12

What is an emulsifier?

A) A molecule that can dissolve in polar substances but not nonpolar substances.

B) A molecule that cannot dissolve in both polar and nonpolar substances.

C) A molecule that cannot dissolve in polar substances but can dissolve in nonpolar substances.

D) A molecule that can dissolve in polar and nonpolar substances.

Answer 12

D) An emulsifier molecule that can dissolve in polar and nonpolar substances.

Question 13

Stearic acid, and other emulsifiers, are large, elongated molecules with a polar head and nonpolar tail. Their shape allows them to:

A) repel other nonpolar or polar substances

B) evenly mix with either nonpolar or polar substances

C) evenly mix with polar substances only

D) evenly mix with either nonpolar substances only

Answer 13

B) evenly mix with either nonpolar or polar substances

Stearic acid, and other emulsifiers, are large, elongated molecules with a polar head and nonpolar tail. Their shape allows them to evenly mix with either nonpolar or polar substances.

Question 14

Proteins are very _______ molecules. They are made of ________ chains of amino acids that fold together into different, specific shapes.

A) large, long
B) tiny, short
C) large, short
D) tiny, long

Answer 14

A) large, long

Proteins are very large molecules. They are made of long chains of amino acids that fold together into different, specific shapes.

Question 15

True or false:

There are 1,022 different amino acids that can form the long chains of proteins

Answer 15

FALSE! There are 22.

Question 16

True or false:

The shape of a protein is determined by two things:

1. The attractions between amino acids in the protein chain. The polar amino acids attract strongly to other polar amino acids. As they move towards each other, the chain bends.
2. The surrounding molecules also interact with amino acids in the protein chain. If the protein is in water, the polar amino acids tend to arrange on the outer edges and the nonpolar amino acids cluster in the center.

Answer 16

TRUE

The shape of a protein is determined by two things:

1. The attractions between amino acids in the protein chain. The polar amino acids attract strongly to other polar amino acids. As they move towards each other, the chain bends.
2. The surrounding molecules also interact with amino acids in the protein chain. If the protein is in water, the polar amino acids tend to arrange on the outer edges and the nonpolar amino acids cluster in the center.

Question 17

Fill in the blank:

When it comes to proteins, ______ matters.

A) size
B) shape
C) money
D) time

Answer 17

B) shape

When it comes to proteins, SHAPE matters.

Question 18

Which of the following is false:

Some of the jobs that proteins do in our bodies include:

A) Fighting off diseases
B) Healing injuries
C) Regulating substances in the body
D) Growth
E) Enzymes – proteins that speed up chemical reactions
F) Weakening your immune system

Answer 18

F)

Some of the jobs that proteins do in our bodies include:

A) Fighting off diseases
B) Healing injuries
C) Regulating substances in the body
D) Growth
E) Enzymes – proteins that speed up chemical reactions

BUT NOT

F) Weakening your immune system

Question 19

To perform their jobs, proteins must have a very specific shape to bind to other substances. This is because:

A) most proteins use a “lock and key” mechanism to activate different reactions and functions. If the “key” doesn’t match the “lock”, the protein cannot bind and the reaction or function will not take place.

B) most proteins use a “lock and key” mechanism to activate different reactions and functions. If the “key” matches the “lock”, the protein cannot bind and the reaction or function will not take place.

Answer 19

A) most proteins use a “lock and key” mechanism to activate different reactions and functions. If the “key” doesn’t match the “lock”, the protein cannot bind and the reaction or function will not take place.

Question 20

Fill in the blank:

A ________ binds to the active site of an enzyme protein. A ______ is a substance on which an enzyme acts.

A) protein(s)
B) antibody / antibodies
C) substrate(s)
D) antigen(s)

Answer 20

C) substrate(s)

A substrate binds to the active site of an enzyme protein. A substrate is a substance on which an enzyme acts.

Question 21

Fill in the blank:

_______ are proteins produced by foreign
disease-causing agents in the body.

A) protein(s)
B) antibody / antibodies
C) substrate(s)
D) antigen(s)

Answer 21

D) antigens

Antigens are proteins produced by foreign
disease-causing agents in the body.

Question 22

Fill in the blank:

_________ are special proteins with specific shapes that form interactions with antigens.

A) protein(s)
B) antibody / antibodies
C) substrate(s)
D) antigen(s)

Answer 22

B) antibody / antibodies

Antibodies are special proteins with specific shapes that form interactions with antigens.

Question 23

True or false:

When an _________ encounters an ________ on a cell, it attracts and binds to it. This marks the cell as being infected, and our immune system destroys it.

A) antibody, antigen
B) antigen, antibody
C) substrate, antigen
D) protein, antigen

Answer 23

A) antibody, antigen

When an antibody encounters an antigen on a cell, it
attracts and binds to it. This marks the cell as being infected, and our immune system destroys it.

Question 24

True or false:

When we catch a flu, the flu virus infects our
cells and forces them to produce flu virus proteins on the surface of the cell membrane.

Answer 24

True

When we catch a flu, the flu virus infects our
cells and forces them to produce flu virus proteins on the surface of the cell membrane.

Question 25

True or false:

Proteins can lose their shape when
exposed to different temperatures.

Answer 25

True

The individual amino acids in proteins start moving around quickly due to increased thermal energy. This causes proteins to unfold.

Question 26

It is very important for proteins to maintain their _____, otherwise they will not work.

A) Polarity
B) Shape
C) Protein Strainginess
D) Aminocity

Answer 26

B) Shape

It is very important for proteins to maintain their shape, otherwise they will not work.

Question 27

True or false:

After a protein loses its shape due to the temperature increasing, we can regain the shape by lowering the temperature back to where it originally was.

Answer 27

False

Proteins do not return to their original shape after the temperature drops.

Question 28

When you are sick and suffering from a fever, the increased temperature of your body causes some of your proteins to lose ______ and stop working.

A) Money
B) State
C) Polarity
D) Shape

Answer 28

Shape

When you are sick and suffering from a fever, the increased temperature of your body causes some of your proteins to lose shape and stop working.

Question 29

Why do you still feel weak for several days after a sickness passes?

A) Your body is adjusting to being at a decreased temperature.
B) The proteins in your body take a vacation after the sickness subsides.
C) Once the fever breaks and the illness subsides, your body recycles damaged proteins to make new ones.
D) The proteins need time to revert to their original shape.

Answer 29

C) Once the fever breaks and the illness subsides, your body recycles damaged proteins to make new ones.

When you have a fever, proteins lose their shape and are irreversibly damaged. Thus, your body must make new ones before it can be healthy again.

Question 30

True or false:

If you have a fever around 107 degrees, your body will shut down if it cannot replace the proteins it lost.

Answer 30

True

Proteins are required for the body to functions. High temperatures damage them and make them unusable.