Chemistry of Life

Hydrogen is a small atom and is more likely to _______ its electron during a covalent sharing.

'lose'

Which symbol separates the reactants from products in a reaction and means "to yield"?

->

Mendeleev developed the periodic table in ______

1869

Base

A substance that decreases the hydrogen ion concentration in a solution.

Acid

A substance that increases the hydrogen ion concentration of a solution.

________ are substances that release hydrogen ions

Acidic substances

Carbonyl Hydroxyl Sulfhydryl

All polar and hydrophilic

Use the accompanying figure to answer the following question. Which letter indicates the neutrons of the atom? https://s3-us-west-2.amazonaws.com/textimgs/DE/bio/Figure_02_01_01_quiz.jpg

B

_________ in the body affect blood pH by creating bicarbonate when the pH needs to be lowered.

Buffers

How are double bonds formed?

Double bonds form when two pairs of electrons are shared

In the following reaction, which chemical is the product? https://s3-us-west-2.amazonaws.com/textimgs/Biology/FormativeAssessment+/Bio_C2_LO6.png

H2O

Phosphate group

Has no carbon and is charged. phosphorus atom covalently bonded to four oxygen atoms

According to the Second Law of Thermodynamics, the randomness of the universe ________.

Is constantly increasing

Why is the amino group basic?

It accepts a H+ ion

_________ of hydrogen ions result in a high pH.

Low levels

Who devised the periodic table of elements?

Mendeleev

Methyl

Nonpolar and hydrophobic R-CH3

Which type of group is more complex than amino groups?

Phosphate group

Potassium has an atomic number of 19. What is its electron configuration?

Shells 1, 2, and 3 are full, and shell 4 has one electron.

Which subshell always fills first?

The 1s

"Burning off" excess weight from Christmas cookies is an example of ________.

The first law of thermodynamics

True or False The s subshell is filled before the p.

True

Entropy is...

a measure of the disorder in a system

Atoms are composed of ______ and ________.

a nucleus; an electron shell

A landscaper wants to plant shrubs that require a soil pH of 7.0 near some evergreen tress. The soil in this location is a pH of 6.0. What can he conclude and what course of action will address the problem? a. The soil has ten times the H+ concentration he desires, so he should add an alkaline material to the soil. b. The soil has a tenth of the H+ concentration he desires, so he should add some acetic acid to the soil. c. The soil has ten times the H+ concentration he desires, so he should add some acetic acid to the soil.

a.

A common household example of a buffer is a. antacid b. bleach c. lemon juice

a. Antacid

Which of the following is the fundamental unit of matter? a. The atom b. The cell c. The electron

a. The atom

Buffers function by...

absorbing excess hydrogen or hydroxide ions

Carboxyl Amino Phosphate

all charged. Carboxyl and Phosphate are acidic. Amino is basic

In an ionic bond, the charge on the cation is ________

always positive

The only functional group that is based on a nitrogen atom is the ______ group.

amino

Which functional group is basic?

amino

The most basic unit of matter

atom

The periodic table displays an element's ______ and atomic number.

atomic mass

Elements are displayed in order of _____________ in the periodic table of elements.

atomic number

Use the accompanying figure to answer the following question. As shown on this graph, which letter indicates the enzyme-mediated reaction? https://s3-us-west-2.amazonaws.com/textimgs/DE/bio/Activation2_updated_quiz.png

b

Identify the open system from the list below. a. A closed bottle b. A dishwasher c. A vaccum sealed bag

b.

The First Law of Thermodynamics addresses ________. a. black holes destroying all the light around them b. conversion of energy to different forms c. the usefulness of an energy resource such as oil

b. conversion of energy to different forms

The substances involved in the _____ of a chemical reaction are the reactants

beginning

Carbon has four electrons in its valence shell and will hence form four ________ to fill its outermost shell.

bonds

Catabolic reactions

break down large chemicals and release energy

Anabolic reactions

build up large chemicals and require energy

Which of the following is a simple polar, branched functional group with no carbon? a. amino group b. methyl group c. sulfhydryl group

c

Which of the following best explains the natural formation of ions? a. an unfilled outer electron shell and electron sharing b. a filled outer electron shell and a large electronegativity differential c. an unfilled outer electron shell and electron transfer

c.

Which of the following is a correct statement? a. Covalent bonds lead to molecules that are stable in air while ionic bonds do not. b. ​Covalent bonds only occur between atoms of similar electronegativities while ionic bonds only occur between atoms of differing electronegativities. c. Ionic bonds to do not share valence electrons while covalent bonds do.

c.

Which of the following would be more polar than a sulfhydryl group? a. an amino group b. a phosphate group c. a hydroxyl group

c.

Which of the reactions below is an anabolic one? a. Digesting a sugar molecule b. Burning a piece of wood c. Synthesizing DNA

c.

The _________ functional group has a central carbon bound to an oxygen atom and two organic side molecules.

carbonyl

The _______ functional group is considered acidic.

carboxyl

The charged ________ group donates hydrogen ions to solution.

carboxyl

Carbonic acid forming into CO2 and H2O is a ________ reaction.

catabolic

When acids are added to a solution, the pH should

decrease

Reversible reactions can proceed in _______ direction.

either

Hydrogen bonds are weak chemical attractions based on differences in ________.

electronegativity

An atom's _______ are disregarded when calculating its mass.

electrons

Chemical reactivity in elements is controlled by _______.

electrons

A(n) _______ speeds up a reaction, while largely remaining unchanged itself.

enzyme

Each carbon can bond with as many as ________ other atoms or molecules.

four

Which type of bond enables many of the properties of water?

hydrogen bond

Which type of bond represents a weak chemical bond?

hydrogen bond

Ultimately, excess ________ build up in the body is prevented by the exhalation of carbon dioxide.

hydrogen ions

Molecules with a hydroxyl group are _______.

hydrophilic

The hydroxyl group makes a molecule polar, which in turn makes it __________.

hydrophilic

Oxygen is more electronegative than sulfur; therefore, a __________ group is more polar than a sulfhydryl group.

hydroxyl

The carboxyl group is considered acidic because...

it releases H+ ions into a solution

When an atom is slightly positive, it is _____ electronegative.

less

The pH scale is a ________ scale

log (times 10 for every number)

A ______ group is based around a carbon bound to hydrogens and an organic molecule.

methyl

The presence of a _______ group makes a molecule hydrophobic.

methyl

The octet rule states that atoms are energetically ______ stable with their outer shell filled with electrons.

more

Blood maintains a ______ pH

near-neutral

Only the amino group contains ______

nitrogen

According to the _______, atoms want their outer electron shells to be filled.

octet rule

Enzymes typically react with...

one specific substrate

A multicellular organism is a(n) ________ system because ________.

open; it exchanges energy with its surroundings

The lower the H+ concentration, the higher the __________

pH value

The more electronegative atom has a

partial negative charge

A ______ group, which is non-carbon based, is charged.

phosphate

Is O-H polar or non-polar?

polar

The behavior of electrons controls the __________ of an atom

reactivity

Catabolic reactions _______ energy.

release

Covalent bonds involve the _______ of electrons.

sharing

When hydrogen is involved in a polar covalent bond, it has a _______.

slight positive charge

According to ________, energy is constantly required to keep entropy low.

the Second Law of Thermodynamics

Excess hydrogen ions accumulated in the body is prevented by...

the exhalation of carbon dioxide

The more electronegative an atom is...

the more strongly it pulls shared electrons toward itself and, therefore, is more polar

In an ionic bond, which element gains electrons?

the nonmetal

According to the First Law of Thermodynamics, ________.

the total amount of energy in the universe is constant

Ions are created by...

the transfer of electrons--gaining or losing electrons, which creates the positive and negative charges

Noble gases rarely form chemical bonds because...

their outermost electron shell is full.

Open and closed systems differ in the way energy is ______ the system.

transferred outside

Open and closed systems differ in the way energy is ________ the system.

transferred outside

A polar carbonyl functional group is the only functional group bound to _____ organic molecules.

two

Using a pH meter, you find the pH of an unknown solution to be 8.0. How would you describe the solution?

weakly basic