elements, molecules and cells

Question 1

chemical elements
- what are they made of
- the structure of an atom
- charges around the atom
- exception element from the norm
- how is an element formed
- what are most abundant elements in living organism
- what is atomic number
- what is atomic mass
- what do happens when the same element has different number of neutrons

Answer 1

• one type of atom
• nucleus and surrounding/orbiting electrons. contains protons, neutrons and electrons
• nucleus positive charge due to protons and surrounding electrons negative charge
• hydrogen has 1 proton and 1 electron
• 2 or more atoms interact
• hydrogen, carbon, nitrogen, oxygen, phosphorus, sulfur
• Atomic number indicates number of protons
• Atomic mass measured in Dalton’s gives mass of the elements atoms, neutrons and protons
• called isotopes

Question 2

molecules and compounds
- what makes up a molecule
- what bond forms between atoms
- what is this type of bond
- what makes up a compound
- difference between compound and a molecule
- difference between organic and inorganic compounds

Answer 2

• made up of the same or different types of atoms
• Atoms joined by covalent bonds
• A molecule with 2 or more different types of atom
• all compounds are molecules, not all molecules are compounds
• Organic compounds contain carbon, Inorganic compounds do not, eg. water

Question 3

covalent bonds
- what is it
- how a single, double, etc bond is formed
- what determines the number of bonds formed

Answer 3

• When 2 atoms share electrons
• If each atom contributes 1 electron, a single bond is formed, 2 electrons, double bond, etc
• Number of bonds formed is determined by distribution of electrons in its electronic structure / orbit

Question 4

groups common in compounds
- H2N
- CH3
- COOH

Answer 4

• amino group
• methyl group
• carboxyl group

Question 5

Ions
- what does it mean to be an ion
- are molecules or compounds ions
- difference between an anion and cation

Answer 5

• an ion is an electrically charged compound
• Molecules are electrically neutral
  - Compounds can be ions (electrically charged)
• atoms with more electrons than protons are negatively charged (anion)
  - Atoms with fewer electrons than protons are positively charged (cation)

Question 6

radicals-
- what is a radical
- why is this different

Answer 6

• When a molecule or ion has an unpaired electron
• Most molecules and ions feature electrons in pairs

Question 7

polar and miscibility-
- what is polar
- what is non polar
- what does polarity impact
- can polar and non polar molecules mix

Answer 7

• when there is 1 negative and 1 positive pole.
• when charge is evenly distributed
• miscibility (ability to mix with other substances)
• polar mix with polar, non polar mix with non polar, but polar and non polar don’t mix readily

Question 8

solutions-
- what is a solution
- what is a solute and solvent
- what is concentration
- normal measurement for conc
- what does water (polar) mix with in the body

Answer 8

• mixing 2 or more substances to a homogenous mixture with the same composition all over its mass
• solvent is the substance present in the highest proportion
• amount of solute in a certain amount of solution
• moles per litre
• hydrophilic polar compounds

Question 9

chemical reactions-
- what are reactants and products
- 3 different types of chemical reaction
- what is the principle of mass conservation
- what similar principle does reactions involving ions adhere to
- how do you know when equilibrium is met
what can determine pH in reactions

Answer 9

• substances consumed and substances produced
• reversible, irreversible, balanced
• atoms are rearranged, not gained or lost
• principle of charge conservation which is the the total amount of electric charge in a closed system must remain constant
• when no change is detected in the concentration of any participating substance
• the concentration of protons/hydrogen ions in a solution

Question 10

cell basics
- Endoplasmic reticulum
- Mitochondria
- Golgi apparatus
- Nucleolus
- Nucleus
- Ribosomes
- Plasma membrane
- Lysosome

Answer 10

• synthesis and storage
• respiration
• protein secretion
• snythesises rRNA
• DNA
• protein synthesis
• transport, structural barrier
• breakdown