Biology Topic B1

• Cell: smallest structural unit of all living organisms.
• Cell-Tissues-Organ-Organ system-organism.
• Prokaryote (bacteria) 'no nucleas - Chromosomes/DNA is found in the cytoplasm.
• Eukaryote (Animal & Plant & Fungi) - Chromosomes are found in the nucleas enclosed by a membrane.
• Structures that are found in cell are called organelles.
• DNA = Deoxyribonucleic Acid
• Chlorophyll uses light to produce glucose.
• Breaking glucose is called respiration.
• Plant cell wall is made from cellulose.

• Mitochondria-structures in the cytoplasm where oxygen is used and most of the energy is released during respiration.Power house of the cell.
• Ribosomes-where protein synthesis takes place.All the proteins synthesistakes place.All the proteins needed in the cell are made here.
• The chemical that makes the cell wall of a bacteria cell is called peptifoglycan.
• Bacteria cells have 2 type of DNA.
• -Chromosomes they have 1 and carry all of there genetic material.
• -plasmids are circular DNA.Plasmids have genes for antibiotic resistance.

Plant Cell

• Cell membrane
• Ribosomes
• Cellulose cell wall
• Mitochondria
• Cytoplasm
• Permanent vacuole
• Chloroplasts
• Nucleas

Animal Cell=      

• Egg Cell
• Sperm cell
• Epithelial Cells
• Ciliated epithelial cells
• These are specialised cells because they perform cerain jobs and function

Cilia are covered in the cell membrane and contain strands of a substance that can contract a cause wavy movement.

- Acrosome contains hydrolylic enzyme that allow them to fuse with the egg.

-The large number of mitochondria are arranged in a spiral to give energy to the tail.

-The cell membranne fuses with the sperm cell membrane.

-The cytoplasm is packed with nutrients, to supply  the fertilised egg cell with energy and raw materials.

-The jelly coat protects the egg cell from any other sperm when fertilisation is complete.

• Movement of water molecules from high potential water to low water potential.
• Water potential - tendency of water molecules to move
• Solute- substance that dissolves
• Solvent-is the liquid in which the solute dissolves.
• Solution-solute +solvent 
• As the concentration of solute increase the water potential decrease
• Pure water- has the highest water potential is 0

• The uptake of particles by cells against a concentration gradient.It requires energy and a carrier protein.
• Active transport is the movement of molecules across a cell membrane from a region of their lower concentration to a region of their higher concentration-in the direction against some gradient or other obstructing factor (often a concentration gradient.

• The movement to particles from an area of high concentration to an area of lower concentration.
• Diffusion refers to the process by which molecules intermingle as a result of their kinetic energy of random motion. 2 Container of gas, A and B separated by a partition. The molecules of both gases are in constant motion and make numerous collisions with the partition.
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