Biochem

Question 1

Atom

Answer 1

• Greek for indivisible
• Smallest particle of an element
• contain protons, neutrons, electrons

Question 2

Ion

Answer 2

• Atoms that have lost or gained electrons
• become positively or negatively charged
• donate e- = +
• accept e- = -

Question 3

Ionic bonding

Answer 3

Chemical bonding resulting from transfer of electrons from one atom to another

Question 4

Covalent bonding

Answer 4

Chemical bond formed by sharing electron pairs between 2 atoms

Question 5

Subatomic particle

Answer 5

• ELECTRONS :Very small subatomic particle
• Make up most volume of atom
• ”-“ charged

Proton: positively charged subatomic particle

Neutron: electrically neutral subatomic particle

Question 6

Isotope

Answer 6

Atoms containing the same number of protons but different numbers of neutrons.

Question 7

Element

Answer 7

• Matter made of only one type of atom.
• Simplest form of matter.
• most common occurring in living things: C, H, O, N

Question 8

Compound

Answer 8

• 2 or more atoms combine to form new substance

Question 9

Inorganic vs Organic compounds

Answer 9

INORGANIC:
Compounds without linked carbons
E.g) NaCl

ORGANIC:
Contain carbons that are linked together
Found in living organisms

Question 10

Acids vs Bases

Answer 10

ACIDS:
Compounds that break down (dissociate) in water and release H or protons.
pH <7

BASES:
Compounds that dissociate in water and release OH ions.
pH >7

Question 11

1. Buffer

2. Catalytic converter

Answer 11

Buffer: Solution that resists change in pH.

Catalytic converter: ensure hydrocarbons are broken down

Question 12

1) Monomer
2) Dimer
3) Polymer

Answer 12

MONOMER: simple compound whose molecules can join together to form polymers
e.g) amino acids

Dimer: a compound composed of two monomers. E.g) dipeptide

POLYMER: a large molecule consisting of chains of rings of linked monomer units
e.g) protein

Question 13

Isomer

Answer 13

A chemical with the same number and types of atoms as another chemical, but possessing dif properties. 
3 COMMON:
Sucrose - glucose + fructose (sugar)
Maltose - glucose +glucose (germ plants)
Lactose - glucose + galactose (milk)

Question 14

Carbohydrates

Answer 14

• can be a single sugar or a polymer of many sugars
• contain C, H, O
  Ratio: 1:2:1
  Structural purposes: component of cell organelles, membranes and cytoplasm.
  Energy: produced by photosynthesis

Question 15

Monosaccharides

Answer 15

• Singer sugar C6H12O6
• Glucose: blood sugar
• Fructose: fruit, honey 2x sweet as glucose
• Galactose: milk sugar, rarely found alone

Question 16

Disaccharides

Answer 16

• formed by joining of 2 monosaccharides
• process called dehydration synthesis:
• reverse of dehydration synthesis is hydrolysis:

Sucrose: glucose + fructose

Maltose: glucose + glucose

Lactose: glucose + galactose

Question 17

Polysaccharides

Answer 17

Formed by union of monosaccharides by dehydration synthesis.

• Starch: storage from of energy in plants
• Glycogen: storage of glucose in animals

Question 18

Lipids function and

3 types

Answer 18

• Long term energy storage.

TRIGLYCERIDES: 1 glycerol and 3 fatty acids. Formed by dehydration synthesis.

SATURATED FIGHT: usually from animals, saturated fatty acids only contain single bonds, and are hard to break down. Solid or semi at room temp.

UNSATURATED: oils, usually from plants, some double bonds, more reactive (easily broken), liquid at room temp.

Question 19

Phospholipids

Answer 19

• Have a phosphate molecule attached to a glycerol backbone
• Polarized molecule: one side positive, one side negative

WAXES: stable, insoluble in H2O

STEROIDS: building material for hormones, vile, etc. Made from cholesterol. 4 fused C rings.

Question 20

Cholesterol

Answer 20

Energy rich molecule used to synthesize hormones.
Accumulation of it in blood vessels leads to heart disease.

LDL’s are bad HDL’s good (take LDL’s to liver to be broken down)

Question 21

Protein

Answer 21

Contains C,H,O,N

A large molecule made of one or more polypeptide chained (PC) in a specific shape.

PC: polymers of amino acids in specific order linked by peptide bonds (covalent bond between amino acids)

Chem messenger, transport, movement, catalysis of cell reactions, defence.

Question 22

Amino acids

Answer 22

Can not be manufactured by body, must be obtained from food.

Question 23

Protein structures:

Primary

Secondary

Tertiary

Quaternary

Answer 23

Primary proteins: Linear arrangements.
Secondary proteins: Coiled or folded due to H bonds.
Tertiary: coiled molecule is further twisted into a folded 3-D shape.
Quaternary: globular proteins formed from interaction between protein chains (hemoglobin, enzymes)
Coagulation: permanent change in protein shape.

Question 24

Nucleic acids

Answer 24

Involved in heredity and protein synthesis

Nucleotide: sugar, phosphate, nitrogen base

DNA: genetic code in chromosomes, blueprint for building proteins.

RNA: Executes DNA’s instructions

Question 25

Vitamins

Answer 25

• inorganic molecules
• not used for making energy
• cannot by synthesized from food
• needed in small amounts for functions

Question 26

Chemical tests

Answer 26

Benedicts Reagent: presence of simple sugars - after heating the Benedict solution remains blue. + heating the b solution yellow–> orange

Iodine test: Test for starch. - iodine solution remains Amber when none present. + turns blue.

Biuret: for protein. - solution remains blue when added to substance w/o. + turns purple

Sudan IV Dye: test for fats. Present = red or pink.

Question 27

Dehydration synthesis

Answer 27

Process by which larger molecules are formed by the removal of water from two smaller molecules.

Question 28

Hydrolysis

Answer 28

Process by which a larger molecule is broken down into two smaller molecules. Water is taken up at the broken bond site.