Chemical Level of Organisation

Question 1

Atoms (Subatomic Particles)

Answer 1

Protons- positive
Electrons- negative
Neutrons- neutral

Question 2

Atomic Structure:
Atomic Number
Nucleus
Electron Cloud
Electron Shell

Answer 2

Atomic Number:
number of protons

Nucleus:
contains protons and neutrons

Electron Cloud:
spherical area containing electrons

Electron Shell:
2D representation of Electron Cloud

Question 3

Elements and Isotopes

Answer 3

Elements:
composed of one type of atom
chemical properties determined by number of protons (atomic number)

Isotopes:
Version of element based on mass number
(number of protons PLUS number of neutrons)

Question 4

Electrons and Energy Levels (shell facts x 3)

Answer 4

Shells hold a limited number of electrons

Lower shells fill first

Outer shell (valence) determines bonding

Question 5

LIKELY IN EXAM:
Chemical Bonds form molecules and compounds
What are molecules and compounds?

Answer 5

Molecules:
two or more atoms joined by strong bonds

Compounds:
two or more atoms of different elements joined by strong or weak bonds

Question 6

Reactions:
Reactants and Products

Answer 6

Reactants:
participants at the start of the reaction
eg. 2 x hydrogen + 1 x oxygen

Products:
what the reaction generates
eg. H2O (water)

Question 7

Ions

Answer 7

Charged atom/element

Cation:
positive charged
given up an electron

Anion:
negatively charged
gained an electron

Question 8

LIKELY IN EXAM:
Chemical Bonds
Chemical Bond Types (x3)

Answer 8

Chemical Bonds involve giving, taking, and sharing electrons

Ionic

Covalent

Hydrogen

Question 9

Ionic Bonds Explanation + Example

Answer 9

One atom GIVES the electron (electron donor)
and becomes a cation (positively charged)

One atom TAKES the electron (electron receiver)
and becomes an anion (negatively charged)

Ionic bonds are the attractions between the cations and anions (positive + negative)

Ionic Compound EXAMPLE= Sodium Chloride
Sodium: Na+ (cation)
Chloride: Cl- (anion)

Question 10

Covalent Bonds Explanation + Examples (x4)

Answer 10

Covalent bonds involve sharing of electrons. One electron is donated by each atom to make a pair.

2 pair= single covalent bond
2 pairs= double covalent bond
3 pairs=. triple covalent bond

Hydrogen H-H (single)
Oxygen O=O (double)
Nitrogen N=N (triple)
Carbon Dioxide O=C=O

Question 11

Nonpolar and Polar Covalent Bonds

Answer 11

Nonpolar = equal sharing
equal pull on electrons

Polar = unequal sharing
one atom has a stronger pull on electrons
Polar bonds form polar molecules
EXAMPLE: water

Question 12

Hydrogen Bonds

Answer 12

Weak polar bonds between adjacent molecules
Formed by slight positive and negative charges

Hydrogen bonds between water molecules create surface tension

Question 13

Chemical Reactions:
Reactant
Product
Metabolism

Answer 13

Reactant: materials going into the reaction
Product: material/s coming out of the reaction
Metabolism: all the reactions occurring at one time

Question 14

Energy
Work
Kinetic Energy
Potential Energy
Chemical Energy

Answer 14

E= capacity to do work
W= movement of object or change in matter
KE= energy of motion
PE= stored energy
CE= potential energy stored in chemical bonds

Question 15

Types of Chemical Reactions (x4)

Answer 15

Decomposition
Synthesis
Exchange
Reversible

Question 16

Chemical Reactions:
Decomposition

Answer 16

Break of chemical bonds
Catabolism

Question 17

Chemical Reactions:
Synthesis

Answer 17

Forming chemical bonds
Anabolism

Question 18

Chemical Reactions:
Exchange

Answer 18

Decomposition THEN Synthesis
Rearranging

Question 19

Chemical Reactions:
Reversible

Answer 19

Amounts of chemicals do not change at equilibrium
Balanced

Question 20

Enzymes

Answer 20

Catalysts for reactions

Lower energy requirements for reactions
Make reactions occur more quickly

Enzymes:
are specific
have saturation limits
are regulated by other cellular chemicals

Question 21

Cofactors
Coenzymes

Answer 21

Cofactors (proteins):
ions or molecules that bind to enzymes before substrates can bind

Coenzymes (vitamins):
non-protein cofactors

Question 22

Enzymes:
exergonic reactions
endergonic reactions

Answer 22

Exergonic- release energy (energy out)

Endergonic- absorb energy (energy in)

Question 23

Inorganic and Organic Compounds

Answer 23

Inorganic: CO2, O, H2O, inorganic acids/bases/salts

Organic: molecules containing carbon and hydrogen
carbohydrates, proteins, lipids, nucleic acids

Question 24

Carbohydrates

Answer 24

Contain: Carbon Hydrogen Oxygen

Monosaccharides- simple sugar
Disaccharised- 2 monosaccharides condensed
Polysaccharides- many monosaccharides condensed

Question 25

Lipids

Answer 25

Contain mostly: Carbon and Hydrogen Fatty acids: chains of C+H with carboxyl group saturated (with hydrogen) unsaturated (with double bonds) Glycerides: fatty acid chains attached to glycerol mono, di, triglycerides Others: steroids, cholesterol, phospholipds, glycolipids

Question 26

Proteins

Answer 26

Contain: Carbon, Hydrogen, Oxygen, Nitrogen Carbon atom + Hydrogen atom + Amino Group + Carboxyl Group + Side Chain (R) 20 Amino Acids that combine to form peptides/proteins AAs are linked by peptide bonds

Question 27

POSSIBLE EXAM Protein Shapes

Answer 27

Primary- sequence of AAs Secondary- hydrogen bonds form spirals or pleats Tertiary- Coiling and folding produce 3D shapes Quarternary- protein complex of interacting polypeptide chains

Question 28

Nucleic Acids

Answer 28

large organic molecules found in cell nucleus DNA RNA

Question 29

DNA and RNA (nucleotides)

Answer 29

DNA + RNA are chains of nucleotides with: a pentose sugar (deoxyribose or ribose) phosphate group nitrogenous base

Question 30

Nitrogenous Bases (DNA and RNA)

Answer 30

Adenine, Guanine, Cytosine, Thymine, Uracil DNA: AGCT RNA: AGCU

Question 31

DNA: Number, Shape, Function

Answer 31

More than 45 million per molecule Paired Strands in coiled double helix Stores genetic information that controls protein synthesis

Question 32

RNA: Number, Types, Function

Answer 32

Varies from fewer than 100- 50,000 mRNA, rRNA, tRNA Performs protein synthesis as directed by DNA

Question 33

High Energy Compounds are derived from... High energy bonds are formed through... EXAMPLE

Answer 33

Most High Energy Compounds are derived from nucleotides High energy bonds are formed through phosphorylation (process of adding a phosphate group to another molecule) Adding a phosphate group to ADP to form ATP

Question 34

pH Neutral pH

Answer 34

the negative logarithm of hydrogen ion concentration of a solution in moles per litre Neutral pH = balance of H+ (hydrogen) and OH- (hydroxide/hydroxyl) pure water = 7.0

Question 34

Human Blood pH Acidic and Alkaline pH

Answer 34

Human Blood pH= 7.35-7.45 Acidic (lower than 7.0) High H and Low OH Alkaline (higher than 7.0) Low H and High OH

Question 35

Acids and Bases

Answer 35

Acids- add Hydrogen ions to a solution Bases- removes hydrogen ions from a solution