Biology unit 1

• KA1.1 - Cell definition

  A cell is the basic unit of life
• KA1.1 - Organelles definition

  Parts of the cell that carry out specialised functions and are enclosed with their own membrane are called organelles.
• KA1.1 - Structures in animal cell (5)

  Cytoplasm, cell membrane,brand, nucleus, ribosomes, mitochondria
• KA1.1 - Structures in plant cells (8)

  Cell membrane, cell wall, vacuole, chloroplast, ribosomes, nucleus, cytoplasm, mitochondria
• KA1.1 - Structures in fungal cell (6)

  Mitochondria, cell wall, nucleus, ribosomes, cytoplasm, cell membrane
• KA1.1 - Structures in bacterial cell (6)

  Cytoplasm,, cell wall, cell membrane, plasmid, ribosomes, bacterial chromosome
• KA1.1 - Cell wall function

  Supports and strengthens cell. Selectively permeable
• KA1.1 - Cell membrane function


  Controls which substances/molecules can enter and exit the cell.
• KA1.1 - Cytoplasm function

  Site of chemical reactions
• KA1.1 - Mitochondria function

  Site of aerobic respiration
• KA1.1 - Chloroplasts function

  Site of photosynthesis
• KA1.1 - Vacuole function

  Contains cells sap, supports the cell
• KA1.1 - Ribosomes function


  Site of protein synthesis
• KA1.1 - Plasmid function

  Circular loop of DNA/ genetic material
• KA1.1 - Nucleus function

  Controls some cell activities
• KA1.1 - What is cell wall in plants made up of

  Cellulose
• KA1.2 - Components of cell membrane

  Protein, phospholipids
• KA1.2 - Molecules small enough to pass through membrane (4)

  Oxygen, carbon dioxide, water, glucose
• KA1.2 - Molecules too large to pass through membrane (2)

  Sucrose, starch
• KA1.2 - Two types of transport

  Active transport, Passive transport
• KA1.2 - Passive transport definition


  The movement of molecules from a higher concentration to a lower concentration, down a concentration gradient, requiring no energy.
• KA1.2 - Active transport definition


  The movement of molecules and ions from an area of low concentration to an area of high concentration against a concentration gradient, requiring energy.
• KA1.2 - Types of passive transport

  Diffusion and osmosis
• KA1.2 - Diffusion definition


  The movement of molecules from a higher concentration to a lower concentration, down a concentration gradient, requiring no energy.
• KA1.2 - Substances which enter a cell by diffusion (3)

  Glucose, Amino Acids, oxygen
• KA1.2 - Substances which exit a cell by diffusion (2)

  Carbon dioxide, urea
• KA1.2 - Osmosis definition

  Movement of water molecules from a higher water concentration to a lower water concentration, down a water concentration gradient and across a selectively permeable membrane
• KA1.3 - Where is DNA found

  In the nucleus in the form of chromosomes
• KA1.3 - Gene definition

  A gene is a section of DNA which codes for a protein
• KA1.3 - DNA structure


  Double stranded helix
• KA1.3 - DNA bases

  Adenine - Thymine, Guanine - Cytosine
• KA1.3 - what does the order of DNA bases in a gene determine?

  Amino acid sequence
• KA1.3 - What do amino acids join together to form?

  Proteins
• KA1.3 - Where are proteins synthesised?

  Ribosomes
• KA1.4 - How are protein shapes and functions determined?


  Sequence of amino acids
• KA1.4 - Protein functions (SHARE)

  Structural proteins, Hormones, Antibodies, Receptors, Enzymes
• KA1.4 - Properties of enzymes (5)

  Speed up cellular reactions and remain unchanged in the process.

  They are made from protein.

  They are biological catalysts.

  They are made by all living cells.

  T hey are specific to their substrate.
• KA1.4 - Stages of enzyme reactions

  1. Substrate binds to enzyme at active site.

  2. Shape of active sire is complementary to specific substrate(s).

  3. Substrate binds to enzyme and forms enzyme-substrate complex which facilitates reaction.

  4. Enzyme action results in product(s).
• KA1.4 - Types of Enzymes reactions

  Degradation and synthesis
• KA1.4 - Degradation definition

  Degradation reactions involve enzymes breaking larger molecules down into smaller molecules.