Science B4, C4
Here are some quick notes to help you with some of the easy basics
- Created by: Sonal
- Created on: 30-12-12 20:04
Cell Structure and Function- Animal
Nucleus- Contains DNA, DNA contains the instructions for making proteins, e.g the enzymes used in the chemical reactions of respiration and photosynthesis
Cytoplasm- Gel like substance where proteins like enzymes are made, some enzyme controlled take place here like anaerobic respiration
Cell Membrane- Holds the cell together & controls what goes in/out, it lets gases, water pass but is a barrier to chemicals
Mitochondria- These are where the enzymes needed for the reactions of aerobic respiration are found and where the reactions take place
Cell Structure and Function- Plant
Rigid Cell Wall- It is made of cellulose and supports the cell and strengthens it
Vacuole- It contains sap which is a weak solution of sugar and salts
Chloroplasts- These are where the reactions for photosynthesis takes place. They contain a green substance called chlorophyll and the enzymes needed for photosynthesis
Equations for Biology
Aerobic respiration- Glucose+Oxygen = Carbon Dioxide+Water
- C(6)H(12)O(6)+6O(2) = 6CO(2)+6H(2)O
Anaerobic respiration- Glucose = Lactic Acid (Energy)
- Glucose = Ethanol+Carbon Dioxide (Energy)
Photosynthesis- Carbon Dioxide+Water = Glucose+Oxygen
- 6CO(2)+6H(2)O = C(6)H(12)O+6O(2)
Brackets- small number at the bottom
Diffusion, Osmosis, Active Transport
Diffusion is the passive overall movement of particles from a region of their higher concentration to a region of their lower concentration
Osmosis is the overall movement of water from a dilute to a more concentrated solution through a semi permeable membrane
Active Transport is the overall movement of chemicals across a cell membrane from a region of lower concentration to a region of higher concentration using energy released by respiration
Elements when heated are...
Some elements have a specific colour when heated:
Lithium (Li) is a red flame
Sodium (Na) is a yellow/ orange flame
Potassium (K) is a lilac flame
Calcium (Ca) is a orangey/red flame
Copper (Cu) is a green flame
Line Spectrum
Each element gives a characteristic line spectrum
When heated the electrons in atoms release energy as light
Different elements emit different wavelengths of light due to the element having different electron arrangement
This means line spectrums can be used to identify elements using a spectroscopy
Group 1
Group 1 elements are called the alkali metals
As you go down the group the reactivity increases
This is because to gain a full outer shell it has to lose an electron (ion)
If the electron is closer to the nucleus then it is harder to lose it whereas the further away the easier to lose an electron
Group 7
Group 7 elements are called the halogens
As you go down the group the reactivity decreases
This is because to have a full outer shell it has to gain an electron (ion)
If the shell needed to gain an electron is nearer to the nucleus it is easier gain an electron whereas the further away the additional electrons are attracted less strongly
Ions
Ions are made when atoms lose or gain electrons
When group 1 elements lose electrons they form positive ions as there are now more protons then electrons
When group 7 elements gain electrons they form negative ions as there are now more electrons than protons
Chemical Equations
(s) - Solid
(l) - Liquid
(g) - Gas
(aq) - Aqueous (dissolved in water)
Halogens
Chlorine- Green/ Yellow- Gas
Bromine- Orange/ Brown- Liquid
Iodine- Grey/ Black- Solid
Comments
No comments have yet been made