Chemistry of Life

Question 1

Element

Answer 1

A substance that cannot be broken down by chemical reactions. Atoms are their smallest units that retain its properties.

Question 2

Trace elements

Answer 2

Required by an organism in only minute quantities (iron, iodine).

Question 3

Isotopes

Answer 3

Forms of an element with differing numbers of neutrons

Question 4

Electronegativity

Answer 4

Tendency to attract electrons

Question 5

Covalent bonds

Answer 5

1. Valence electrons are shared between atoms
2. Most common bond in bio
   3.

Question 6

Nonpolar covalent

Answer 6

Electrons are shared equally

Question 7

Polar covalent

Answer 7

Electrons are shared unequally due to unequal negativities. Causes areas of partial positive and partial negative charges.

Question 8

Hydrogen bonds

Answer 8

1. Bond bases in nucleic acids and form between water molecules
2. Weak bonds that form between hydrogen (partial positive) and oxygen or nitrogen (strongly electronegative)
3. Water can form 4 hydrogen bonds at a time

Question 9

Properties of water

Answer 9

1. Cohesion- creates surface tension and allows molecules to cling together
2. High specific heat- large amount of heat to boil
3. Less dense as a solid, allows ice to float
4. Important solvent for polar substances
5. All are due to hydrogen bonds

Question 10

Cohesion

Answer 10

1. Allows for adhesion and transpiration. Occurs in thin vessels (capillary action).
2. Adhesion- water molecules stick to other substances
3. Transpiration- water moves up xylem and evaporates from leaves- molecules cling to each other by cohesion and to plant vessel walls by adhesion.

Question 11

High specific heat

Answer 11

Takes a lot of heat to heat up water, so it can remain in our bodies without boiling. Keeps temperature of oceans stable.

Question 12

Expansion on freezing

Answer 12

Makes ice less dense, letting it float and protecting organisms that live in water.

Question 13

Acids

Answer 13

Excess of hydrogen ions, have a pH below 7

Question 14

Bases

Answer 14

Excess of hydroxide ions (OH), have a pH above 7

Question 15

Buffers

Answer 15

Minimize changes in pH by accepting or donating hydrogen ions depending on the change. Carbonic acid is a buffer to control pH in the human body and in oceans.

Question 16

pH

Answer 16

Scale is logarithmic- measures hydrogen ions by a factor of 10. pH of 3 is ten times more acidic than 4.

Question 17

Polymers

Answer 17

Chain of building blocks, individual are called monomers

Question 18

Organic compounds

Answer 18

All contain carbon, and most contain hydrogen and oxygen, connected by covalent bonds.

Question 19

Properties of carbon

Answer 19

Can form up to 4 covalent bonds, can form chains, ring shaped molecules, or branches.

Question 20

Isomers

Answer 20

Same molecular formula but differ in the arrangement of atoms, which creates different properties. Examples are glucose and fructose, which both have the same formula.

Question 21

Functional groups

Answer 21

Create diverse properties. 
Alcohol (OH)
Organic acid (COOH)
Amino (NH2)
Phosphate (PO3)

Question 22

Carbohydrates

Answer 22

1. Contain Carbon, Hydrogen, and Oxygen in a 1:2:1 ratio
2. Soluble in water
3. Classified as mono, di, or polysaccharides

Question 23

Monosaccharides

Answer 23

1. Simple sugars/monomers that are used as energy for cells (glucose, fructose).
2. Depicted as straight or as rings (C6H12O6)

Question 24

Disaccharides

Answer 24

1. Form through dehydration synthesis

2. Uses 2 sugar molecules. 2 glucose molecules form maltose

Question 25

Polysaccharides

Answer 25

1. Repeated units of monosaccharides 2. Energy storage. Glycogen for animals, starch for plants 3. Structural support. Cellulose for plant cell walls, chitin for insect exoskeletons

Question 26

Dehydration Synthesis

Answer 26

Bonds form by removing a water molecule

Question 27

Hydrolysis

Answer 27

Water is added to break bonds.

Question 28

Lipids

Answer 28

1. Contain Carbon, Hydrogen, and Oxygen, but not in a 1:2:1 ratio. 2. Most are insoluble in water and repel it 3. Also can contain other elements of phosphorus, nitrogen, and sulfur 4. Types: fats/triglycerides, steroids, phospholipids 5. Monomers- glycerol and fatty acids

Question 29

Functions of lipids

Answer 29

1. Energy storage- store more calories than carbs | 2. Protection and insulation of vital organs

Question 30

Saturated

Answer 30

Single bonds, these types of fats are unhealthy. Solid at room temp

Question 31

Triglycerides

Answer 31

1. Classified as saturated or unsaturated | 2. Glycerol with 3 fatty acids (long chain of carbons covered in hydrogen) attached to it

Question 32

Phospholipids

Answer 32

1. Diglyceride (tail) with negatively charged phosphate (head). Head is polar and hydrophilic 2. Make up cell membranes

Question 33

Steroids

Answer 33

1. Large lipids formed by 4 connected rings of Carbon | 2. Form of some hormones, like testosterone or estrogen, and cholesterol

Question 34

Proteins

Answer 34

1. Polymers of amino acids 2. Shape is determined by its amino acid content, and its shape (conformation) determines function 3. Has 4 levels of structure

Question 35

Amino acids

Answer 35

1. Has amino group (NH2), carboxyl group (COOH), R group, and hydrogen atom 2. R group creates the differences between amino acids

Question 36

Peptide bond

Answer 36

1. Bonds amino acids. A chain of amino acids is a polypeptide. Polypeptides fold in on each other to create a protein. 2. Form through dehydration synthesis between amino and carboxyl groups

Question 37

How is a protein denatured?

Answer 37

1. Through heat, change in pH, or other disturbance | 2. Changes its shape, and therefore it loses its ability to function.

Question 38

Primary structure of proteins

Answer 38

Genetically determined amino acid sequence, and is determined by the number, kind, and order of amino acids

Question 39

Secondary Structure

Answer 39

1. 2 3D shapes formed by hydrogen bonding between polypeptide backbone 2. Alpha is a coiled shape, beta is a pleated sheet 3. Amino acids close to each other are interacting

Question 40

Tertiary Structure

Answer 40

1. Reactions between R groups, amino acids that were far away can now interact 2. Develops a complex shape

Question 41

Quaternary Structure

Answer 41

1. Not every protein gets to this stage 2. Polypeptide chains interact 3. Hemoglobin is an example of this

Question 42

Chaperone proteins

Answer 42

Help proteins to fold

Question 43

Nucleic Acids

Answer 43

1. Monomers are nucleotides 2. Found in nucleus for DNA and cytoplasm for RNA of cells. 3. Contain C, H, O, N, P 4. Have directionality by 3 and 5 carbons of the sugar

Question 44

Nucleotides

Answer 44

Composed of nitrogenous base (C, T, G, A, or U), sugar (ribose or deoxyribose) and a phosphate group.

Question 45

RNA

Answer 45

Single stranded

Question 46

DNA

Answer 46

Double stranded, molecule of heredity