How Life Works: Chapter Two HW and PPT Notes

A central carbon atom (alpha carbon) covalently linked to four groups:

-Carboxyl (COOH), Amino (HN2), Hydrogen (H), and the R group (side chain)

Nucleotides are composed of three components:

1. A 5-carbon sugar (ribose or deoxyribose) 2. A base containing nitrogen 3. And one or more phosphate groups

Which one of the following represents the pH of a solution with the highest concentration of hydrogen ions?

1.0

Molecules made primarily of carbon and hydrogen are called hydrocarbons. How many hydrogen atoms are present in the following molecule? A hydrocarbon chain of five carbon atoms with one double bond and the rest single bonds.

10

Molecules made primarily of carbon and hydrogen are called hydrocarbons. How many hydrogen atoms are present in the following molecule? A five-carbon hydrocarbon molecule with four of the carbons linked by a single covalent bond, and with the fifth carbon attached by a single bond as a branch to the second carbon in the chain.

12

Molecules made primarily of carbon and hydrogen are called hydrocarbons. How many hydrogen atoms are present in the following molecule? A hydrocarbon chain of five carbons joined to each other by single covalent bonds.

12

Today, there are ___ elements known, __ occur naturally and __ have been created artificially in the laboratory.

180; 94; 24

Orbitals exist in different energy levels, or shells. The first shell contains __ spherical orbital. The second shell has __ orbitals. The first shell can contain up to __ electrons. The second shell can contain up to __ electrons.

1; 4; 2; 8

The maximum number of electrons in any orbital is ___ .

2

How many electron orbitals does a carbon atom possess?

5

14C is an isotope of carbon that possesses:

6 protons, 8 neutrons, and 6 electrons.

Pure water has a pH of __, which is also the pH of most of our cells.

7

Molecules made primarily of carbon and hydrogen are called hydrocarbons. How many hydrogen atoms are present in the following molecule? A hydrocarbon chain of five carbon atoms with two double bond and two single bonds.

8

Which of the following ranks the elements carbon, sodium, calcium, and iodine in order of greatest abundance in living organisms?

C → Ca → Na → I

The structural diversity of carbon-based molecules is based upon which of the following properties? A. the ability of those bonds to rotate freely B. the ability of carbon to form four covalent bonds C. None of these choices is correct. D. All of these choices are correct. E. the orientation of those bonds in the form of a tetrahedron

D. All of these choices are correct.

True or False: Fatty acids that contain double bonds are saturated—saturated with hydrogen atoms.

False, the do NOT.

_______ are long chains of carbons attached to a carboxyl group at one end.

Fatty acids

Which of the following ranks the elements carbon, sodium, calcium, and iodine in order of decreasing number of valence electrons?

I → C → Ca → Na

Which of the following ranks the elements carbon, sodium, calcium, and iodine in order of decreasing number of electrons?

I → Ca → Na → C

Which of the following ranks the elements carbon, sodium, calcium, and iodine in order of decreasing number of energy shells/levels?

I → Ca → Na → C

Which of the following ranks the elements carbon, sodium, calcium, and iodine in order of decreasing number of protons?

I → Ca → Na → C

Two atoms are attracted to each other because of their differences in charge - what kind of bond did they form?

Ionic

Which one of the following biological polymers is defined by a physical property rather than a chemical structure?

Lipids.

_____ is more electronegative than hydrogen and attracts electrons more than does hydrogen.

Oxygen

_______ are composed of a glycerol backbone, two fatty-acid chains, and a phosphate-containing head group.

Phospholipids

The ______ is what distinguishes one amino acid from another.

R group

______, like cholesterol here, are composed of many carbon atoms bonded to form rings.

Steroids

True or false: although monosaccharides can exist in linear form, virtually all cellular monosaccharides are found in circular form.

True.

True or false: elements in the same horizontal row have the same number of shells and the same number of types of orbitals.

True.

True or false: the bases in nucleic acids are single-ring pyrimidines (T, C, U) or double-ring purines (A, G).

True.

____ is able to resist temperature change more than other substances because in order for its temperature to increase, hydrogen bonds must first break.

Water

A phosphodiester bond is formed between:

a 5' phosphate and a 3' hydroxyl group.

A ____ atom behaves as if it has four unpaired electrons.

carbon

The four major elements are ___, ___, ____, and _____ making up 94% of the dry mass.

carbon, oxygen, hydrogen, and nitrogen

Phospholipids are a major component of the ______.

cell membrane.

The carbon of the carboxyl group of one amino acid is linked to the nitrogen in the adjacent amino acid by a ___ ____ bond.

covalent peptide

If you isolate a single nucleotide from a nucleic acid chain and determine that the nitrogenous ring structure is cytosine, you could say with certainty that the nucleotide could have come from:

either DNA or RNA.

The negatively charged _____ move around the nucleus.

electrons

Triacylglycerols are used primarily for:

energy storage.

Monosaccharides are attached to one another by covalent bonds called ______ bonds.

glycosidic

All lipids are______.

hydrophobic

Water is the..

medium of life.

Electrically neutral particles called ____ .

neutrons.

Adjacent pairs of nucleotides are joined together by _______ bonds.

phosphodiester

Which one of the following elements would most likely have bonding properties similar to nitrogen (N)? Consult the periodic table in Figure 2.3 if necessary.

phosphorous (P)

Water is a ___ molecule with a partial positive charge at the hydrogens and a partial negative charge at the oxygen.

polar

When amino acids are linked together in a chain, they form a _____.

protein.

Cellular processes depend on a few classes of carbon-based molecules:

proteins, nucleic acids, carbohydrates, and lipids.

The nucleus is made up of positively charged particles called _____ .

protons.

The double bond is _____ than a single bond and is not free to rotate, so two carbon atoms connected by a double bond are in the ____ geometrical plane.

shorter; same

Using the periodic table in Figure 2.3, determine which one of the following elements would be found in least abundance in a living cell.

silicon (Si)

Two molecules of hydrogen gas and one molecule of oxygen can react to form two molecules of water. In this reaction, the numbers of each type of atom are conserved, but...

their arrangement is different.

Hydrocarbon chains of fatty acids contain no polar covalent bonds, and are ______.

uncharged.