Chemistry

Question 1

Define matter. Define chemistry. Define energy

Answer 1

Matter has mass and occupies space
Energy has force and direction

Electromagnetism is the principal form of energy that reacts with organisms. Heat, light, radiation, microwaves etc.​

All electromagnetic energy is related, differing only in how energetic it is. Cosmic rays are the most energetic, while radio waves are the least. In between is atomic radiation , UV, visible light, infrared etc.​

Visible light is different only in that we can see it, Infrared is felt as heat, UV because it burns,

Matter can exist in any one of three states – solid, liquid or gas, depending on how much heat is present.​

All matter is composed of atoms. Solids have atoms closely aligned with each other, liquids less closely and gases with the atoms spaced widely apart.​

Atoms can interact with each other to produce complex molecules through a process called chemistry.

Question 2

What is an electron shell?
The first shell closest to the nucleus can hold how many electrons? 2
The second shell can hold how many? 8

Answer 2

Atoms like to have filled outer energy levels​

They are willing to gain or lose electrons in order to achieve this.​

However, when they gain or lose electrons they are no longer stable neutral elements, but charged ions.​

If their charge is positive, they are cations​

If their charge is negative, they are anions

Question 3

ionic bonding

Answer 3

When electrons are transferred between two or more atoms.​

The atom losing an electron becomes positively charged and is said to be oxidized.​

The atom gaining an electron becomes negatively charged and is said to be reduced.​

This is a redox reaction

Question 4

What is atomic number?

Answer 4

the number of protons in the nucleus of an atom, which determines the chemical properties of an element and its place in the periodic table

Question 5

What is a valence shell of atoms?

What are valence electrons and why are they important?

Answer 5

hey are important because they determine how an atom will react
The outer shell (valence) must have it’s outer shetl filled - so 2, 8,

Question 6

Define the octet rule.

Answer 6

The duet rule states that hydrogen and helium may have no more than two electrons in their valence shell

Question 7

What is a cation?

What is an anion?

Answer 7

Cations is a positively charged ion. An anion has more electrons than protons, consequently giving it a net negative charge.

Question 8

Define covalent bond.

What is electronegativity of an atom?

Answer 8

A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. Electronegativity is a measure of an atom’s ability to attract shared electrons to itself. On the periodic table, electronegativity generally increases as you move from left to right across a period and decreases as you move down a group.

Question 9

Define nonpolar covalent bonds. (Figure 2.6a).

Define polar covalent bonds (Figure 2.6b).

Answer 9

Equal sharing of electrons.
Unequal sharing of electrons. Water is a good example of a polar covalent bond. It has both ionic and covalent properties.

Question 10

What is known as dipoles?

Answer 10

It is a dipole - there is a positive and negative end.

Question 11

Explain how hydrogen bonds are formed between molecules made of polar covalent bonds. (Figure 2.7).

Answer 11

he hydrogen atoms are bound to the highly electronegative oxygen atom (which also possesses two lone pair sets of electrons, making for a very polar bond.

Question 12

Hydrogen bonds are responsible for some of the key properties of water. Can you explain this statement with the surface tension of water?

Answer 12

The hydrogen bonds between water molecules give water the ability to hold heat better than many other substances.

Question 13

What is a catabolic reaction?

Answer 13

Catabolic reactions involve the breakdown of large, organic molecules into smaller, simpler ones, accompanied by a release of energy. (breakdown)

Question 14

What is an anabolic reaction?

Answer 14

(build) synthesize larger molecules from smaller constituent parts, using ATP as the energy source for these reactions. Anabolic reactions build bone, muscle mass, and new proteins, fats, and nucleic acids.

Question 15

What is an enzyme? How does it work?

Answer 15

Enzymes perform the critical task of lowering a reaction’s activation energy—that is, the amount of energy that must be put in for the reaction to begin

Question 16

Define acid. (Figure 2.12b)

Answer 16

. A group of ionically bonded compounds that play a critical role in the human body are acids, bases and salts

Question 17

At what pH is the solution neutral?

Answer 17

7

Question 18

A solution is acidic at what pH?

Answer 18

Anything below 7.0 is acidic, and anything above 7.0 is alkaline, or basic.

Question 19

Most body fluids are slightly basic pH: What is the pH of blood?

Answer 19

Usually the body maintains the pH of blood close to 7.40.

Question 20

What is a buffer?

Answer 20

A buffer is a solution that can resist pH change upon the addition of an acidic or basic components. It is able to neutralize small amounts of added acid or base, thus maintaining the pH of the solution relatively stable.

Question 21

What is an electrolyte?

Answer 21

electrolyte is a compound which produces ions when dissolved in a solution such as wate

Question 22

Monomers and Polymers:

Answer 22

A monomer is a type of molecule that has the ability to chemically bond with other molecules in a long chain; a polymer is a chain of an unspecified number of monomers.

Question 23

Describe dehydration synthesis

Answer 23

Dehydration synthesis refers to the formation of larger

Question 24

What are the three elements that make carbohydrates?

What is the ratio of the three elements in carbohydrates?

What is the main function of carbohydrates?

What are monosaccharides? List examples of the most abundant monosaccharides in the body. (Figure 2.14).

Answer 24

Carbohydrates are a class of chemical compounds composed of carbon, hydrogen, and oxygen 1:2:1 ratio, respectively.

They provide cells with energy, store energy, and form structural tissues

A monosaccharide is the most basic form of carbohydrates. Monosaccharides can by combined through glycosidic bonds to form larger carbohydrates, known as oligosaccharides or polysaccharides

Question 25

What are saturated , monounsaturated and polyunsaturated fatty acids? (Figure 2.17c).

Answer 25

Fats may be saturated (having single bonds) or unsaturated (having double bonds). Unsaturated fats may be cis (hydrogens in same plane) or trans (hydrogens in two different planes). Olive oil, a monounsaturated fat, has a single double bond whereas canola oil, a polyunsaturated fat, has more than one double bond.

Question 26

What are lipids?

What is triglyceride, and how is it formed? (Figure 2.18).

Answer 26

Lipids are a group of structurally and functionally diverse organic compounds that are insoluble in water. Certain classes of lipids, such as fats, phospholipids, and steroids are crucial to all living organisms. They function as structural components of cellular membranes, energy reservoirs, and signaling molecules.

Mono-, Di-, and Triglycerides consist of 1-3 fatty acids plus a glycerol.
Mono- and Di- phospholipids consist of 1-2 fatty acids and a glycerol phosphate.
Steroids are multi-ring compounds and are all monomers. Cholesterol is the best known.

Question 27

What is a phospholipid?

Answer 27

Phospholipids, also known as phosphatides, are a class of lipids whose molecule has a hydrophilic “head” containing a phosphate group, and two hydrophobic “tails” derived from fatty acids, joined by a glycerol molecule

Question 28

What are steroids? What is the steroid that forms the basis for all the other steroids in the body

Answer 28

Steroids are non-polar3 molecules produced from the precursor cholesterol. Four interconnected rings of carbon atoms form the skeleton of all steroids

Question 29

The complex structure of a complete protein is divided into four levels (Figure 2.23). Describe each level of protein structure.

Answer 29

The shape of a protein can be described by four levels of structure: primary, secondary, tertiary and quaternary.
Primary structure is the unique and linear sequence of amino acids in a protein. It is the sequence in which amino acids are added to a growing polypeptide during translation.

Small changes in primary structure can result in large changes in protein shape and function.

Secondary structure describes regions where the polypeptide is folded into localized shapes. There are two types of secondary structure (alpha helix and Beta pleated sheet).

Tertiary structure is the overall shape of the protein. Most proteins (e.g. lysozyme, hemoglobin and insulin) have a compact, globular tertiary structure.

Quaternary structure occurs in proteins that are made up of more than one polypeptide chain.

https://quizlet.com/14512359/c1-sl-biocards-flash-cards/

Question 30

Explain protein denaturation. What factors can denature a protein? What happens when a protein is denatured?

Answer 30

tbd

Question 31

Can you denature the primary structure of a protein?

Answer 31

Primary structure, such as the sequence of amino acids held together by covalent peptide bonds, is not disrupted by denaturation

Question 32

The nucleotide structure is composed of three parts. List the three parts (Figure 2.24a):

Answer 32

The building blocks of DNA are nucleotides, which are made up of three parts: a deoxyribose (5-carbon sugar), a phosphate group, and a nitrogenous base (Figure 9.3). There are four types of nitrogenous bases in DNA.

Question 33

There are two types of nitrogenous bases: purines and pyrimidines. Describe them and name the nucleotides included in each group (Figure 2.24b).

Answer 33

Five types of nitrogenous bases
– Pyrimidines—single-ring bases
o Cytosine
o Uracil
o Thymine
– Purines—double-ring bases
o Adenine
o Guanine
• Nitrogenous bases within either group differ in
functional groups attached to ring

Question 34

hat is Adenosine triphosphate (ATP) (Figure 2.25a).
How is ATP synthesized? Where is the energy stored in ATP? (Figure 2.25b).
The production of large quantities of ATP requires which molecule? How do we get the molecule?

Answer 34

energy-carrying molecule found in the cells of all living things.

ATP is a phosphorylated nucleotide. It is composed of adenine, ribose, and three phosphate groups. “Adenosine” comes from adenine and ribose, while “triphosphate” is given by the three phosphate groups.

Question 35

Where is DNA found?

Answer 35

nucleus

Question 36

What are the main structural features of DNA (sugar, bases, strands and how that are arranged, complementary base pairing rule, hydrogen bonds between bases, antiparallel strand).

Answer 36

Double stranded. Composed of phosphate, a sugar called deoxyribose, and four nitrogenous bases—adenine, guanine, cytosine, and thymine. Two of the bases, adenine and guanine, have a double-ring structure characteristic of a type of chemical called a purine.

Question 37

What is the main function of DNA?

Answer 37

It stores instructions for making other large molecules, called proteins. These instructions are stored inside each of your cells, distributed among 46 long structures called chromosomes.

Question 38

What is the structure of RNA, and where is it found? What is the function of RNA (Figure 2.26b).

Answer 38

RNA consists of ribose nucleotides (nitrogenous bases appended to a ribose sugar) attached by phosphodiester bonds, forming strands of varying lengths. Single stranded composed of adenine, guanine, cytosine, and uracil, which replaces thymine in DNA.

Question 39

Why is DNA replication important during cell division. DNA replication follows specific steps (Figure 3.34). Using the figure answer the specific steps:

Answer 39

The purpose of DNA replication is to produce two identical copies of a DNA molecule. This is essential for cell division during growth or repair of damaged tissues. DNA replication ensures that each new cell receives its own copy of the DNA.

initiation, elongation, and termination.

Question 40

1. DNA strands are separated by which enzyme?
   2/ Which enzyme builds RNA primer on the exposed DNA strands?
2. Which enzyme adds nucleotides to the RNA primer?
   DNA polymerase proceeds in opposite directions along each strand. Why?
3. Why is the replication called semiconservative replication?

Answer 40

Helicase
Primase
DNA polymerase

4. each copy contains one old original strand

Question 41

How are disaccharides formed? (Figure 2.15)

What are polysaccharides?

What is the function of polysaccharides?

Answer 41

How are disaccharides formed? (Figure 2.15).All polysaccharides are formed by the same basic process: monosaccharides are connected via glycosidic bonds.
What are polysaccharides? Give examples of the main polysaccharide in plants and animals? What is the function of polysaccharides? (Figure 2.16).Due to the presence of multiple hydrogen bonds, the water cannot invade the molecules making them hydrophobic