Concept Checks

Question 1

Explain how table salt has emergent properties.

Answer 1

Sodium by its self is a metal

Chlorine by its self is a toxic gas

Together they make something edible

Question 2

An Li atom has 3 protons and 4 neutrons. what is the mass number

Answer 2

7

Question 3

Radioactive isotop notation for N with 7 protons and 8 neutrons

Answer 3

⁸₇ N

Question 4

³¹P differs from ³²P how?

Answer 4

1 more neutron

Question 5

The reactivity of an atom arises from:

Answer 5

The existence of unpaired electrons in the valence shell

Question 6

An anion has more ___ than ___

Answer 6

electrons than protons

Question 7

What is electronegativity and how does it affect interactions with water molecules?

Answer 7

electronegativity is the attraction for electrons in a covalent bond.

Oxygen is more electronegative than hydrogen resulting in a partial negative charge on the oxygen and partial positive on hydrogen.

Opposite partial charges on neighboring water molecules result in hydrogden bonding

Question 8

Describe how properties of water contribute to the upward movement of water in a tree

Answer 8

H-bonds help water molecules stick together

Cohesion helps them travel up vessels in tree

adhesion helps go against gravity

Question 9

how can the freezing of water crack a boulder?

Answer 9

As water freezes the molecules expand, if they expand in a boulder it will crack

Question 10

How can an insect that can walk on water with hydrophobic legs?

What if they were hydrophilic?

Answer 10

Hydrophobic legs repel water allowing it to keep from breaking through the sruface

hydrophilic legs would draw water up making it more difficule to stay on top of water.

Question 11

HCl is a strong acid that dissociates in water. what is the pH of 0.01M HCl?

Answer 11

[H⁺] = 0.01 M = 10^-2M

So pH = 2

Question 12

Write the dissociation reaction for the buffer CH₃OOH.

Answer 12

CH₃OOH —> CH₃OO^- + H⁺

Question 13

Hydration shell:

around a negative ion

Answer 13

surrounded by the partially positive hydrogens

(water molecule)

Question 14

Hydration shell:

around a positive ion

Answer 14

surrounded by the partially negative oxygens

(water molecule)

Question 15

How many water molecules are needed to hydrolize a polymer that is 10 monomers long?

Answer 15

9 waters

Question 16

What are the 4 main classes of macromolecules?

which is not made up of polymers?

Answer 16

Carbohydrates, Proteins, Nucleic Acids and Lipids

Lipids are not polymers

Question 17

What is the formula for a monosaccaride with 3 carbons?

Answer 17

C₃H₆O₃

Question 18

Forumla of molcule after you dehydrate and join two C₆H₁₂O₆

Answer 18

C₁₂H₂₂O₁₁

Question 19

What parts of the polypeptide participate in the bonds that hold together secondary structure?

Tertiary structure?

Answer 19

Secondary - H bonds between the atoms of the polypeptide backbone

Tertiary - interactions between atoms of the side chains of the amino acid subunits.

Question 20

Where would you expect a polypeptide region rich in the amino acids valine, leucine, and isoleucine to be located in a folded polypeptide?

Answer 20

Those are all non-polar, hydrophobic amino acids. they would be in the interior

Question 21

The structural level of protein least affected by a disruption in h-bonding is?

Answer 21

Primary

Question 22

According to the fluid mosaic model of the membrane structure, proteins of the membrane are mostly

Answer 22

embedded in the lipid bilayer

Question 23

What property allows oxygen and carbon dioxide to cross lipid bilayer without the aid of membrane proteins?

Answer 23

Small Nonpolar molecules