B4

Respiration; A series of chemical reactions in cells that release energy for the cell to use

Photosynthesis; The process in green plants that uses energy from sunlight to convert CO2 and H2O into sugar glucose

Denatured; A change in the usual nature of something. When enzymes are denatured by heat and their structure.

Chloroplast; An Organelle found in some plant cells where photosynthesis takes place.

Cytoplasm; Gel enclosed by the cell membrane that contains the Cell Organelles such as mitochondria.

Osmosis; The diffusion of water across a partially permeable membrane. 

Quadrat; A square grid of a known area that is used to survey plants in a location.

Mitochondria; An Organelle in animal and plant cells where respiration takes place.

Lactic Acid; waste product from anaerobic respiration in animals

Fermentation; Chemical reactions in living organisms that release energy from organic chemicals, such as yeast producing alcohol from the sugar in grapes. 

There are 7 life processes

All living organisms carry out the 7 processes of life. (viruses are not living as they do not carry out the 7 life processes of life)

Movement

Respire

Sense

Grow

Reproduce

Excrete

Feed

Enzymes are;

• A Natural Catalyst
• Speed up chemical reactions in cells
• Proteins
• Made in a cell, genes carry the instructions to make enzymes.
• Every reaction in a cell needs its own enzyme. The reacting molecules must fit exactly in the active site of the enzyme. 
• Every enzyme has its own unique shape.

Enzymes work best at their optimum temperature

• Below the optimum temperature, reactions are slow
• If the temperature is too high, an enzyme changes its shape. It no longer catalysts its reactions. The enzymes has been Denatured.

Plants make their own food by photosynthesis. Photosynthesis is;

Carbon Dioxide + Water = Glucose + Oxygen

Photosynthesis takes place in the Chloroplasts of a cell.

Photosynthesis makes Glucose, Glucose can be used by the plant for;

1) making other chemicals needed for cell growth, glucose is converted into carbohydrates, fats, and proteins. Cellulose and Starch.

2) Storing energy in Starch molecules, excess Glucose converted into Starch. Starch is stored in leaf cells.

3) Releasing energy in Respiration, Glucose molecules are broken down by Respiration, releasing energy stored in the molecules. Energy is used to power chemical reactions.

Diffusion is;

The movement of particles from an area of high concentration to an area of low concentration.

Osmosis is the;

Movement of water molecules from an area of high water concentration to an area of low water concentration through a Partially Permeable Membrane.

Partially Permeable Membrane = Cell Membrane

• Uses Oxygen
• Uses Glucose
• Releases energy (lots)
• Produces Carbon Dioxide and Water
• Takes place in Mitochondria

It happens in plant and animal cells, and in some microorganisms. 

Glucose + Oxygen = Carbon Dioxide + Water

• No Oxygen present
• Releases Small amounts of energy

Happens in plant and animal cells, and in some microorganisms, when there is little or no oxygen, for example;

• Parts of plants, such as roots in waterlogged soils, and germinating seeds
• Some microorganisms, such as yeast (brewing and baking), Lactobacilli (Cheese and yogurt making), and Bacteria in puncture wounds

Some produces ethanol and carbon dioxide instead of lactic acid

Anaerobic Respiration in animal cells, and in some bacteria;

Glucose = Lactic Acid

In plant cells, and in some microorganisms such as yeast, Anaerobic Respiration forms different products;

Glucose = Ethanol + Carbon Dioxide 

3 factors which can limit the speed of Photosynthesis; Light Intensity, Carbon Dioxide concentration, and Temperature

Light Intensity; without enough light, a plant cannot photosynthesise very quickly, even if there is plenty of light, a plant cannot photosynthesise if there is insufficient Carbon Dioxide

Carbon Dioxide concentration; Sometimes photosynthesis is limited by the concentration of Carbon Dioxide in the air. Even if there is plenty of light, a plant cannot photosynthesise if there is insufficient Carbon Dioxide.

Temperature; If it gets too cold, the rate of photosynthesis will decrease. Plants cannot photosynthesis if it gets too hot.