Topic 1 – Key concepts in biology

• What are prokaryote cells?

  Simple Cells with no nucleus.
• What is an example of a prokaryotic cell?

  Bacterium
• what are Eukaryote cells?


  Cells with a nucleus and membrane-bound organelles. (Complex cells).
• What is an example of a Eukaryotic cell? 


  Animal and Plant cells.
• What are the subcellular structures found in an animal cell?

  Nucleus, mitochondria, Cytoplasm, Cell membrane, Ribosomes.
• What are the subcellular structures found in a plant cell?


  Nucleus, Cytoplasm, Cell membrane, Mitochondria, Ribosomes, Cell wall, Vacuole, chloroplasts.
• What are the subcellular structures found in a Bacterial cell?


  Chromosomal DNA, Ribosomes, Cell membrane, Plasmid DNA, Flagellum.
• What is the function of a Nucleus?

  Contains genetic material (DNA) that controls the cell's activities.
• What is the function of the cell membrane?

  Controls the passage of substances in and out of the cell.
• What is the function of Mitochondria?

  Aerobic respiration, where energy is released (From Glucose and Oxygen).
• What is the function of the Ribosome?

  Protein synthesis - The production of Certain Animo acids to form a certain type of protein.
• What is the function of the Cell wall?

  Provides structural support using cellulose and is found in plant cells only.
• What is the function of the vacuole?

  Stores cell sap containing water, sugars, and minerals. It is found in plant cells only.
• What is the function of Chromosomal DNA?

  Contains genetic information for cell functions and is found in Bacterial Cells only.
• What is the function of the cytoplasm?

  A solvent in which chemical reactions take place.
• what is the function of a chloroplast?

  Photosynthesis - the production of glucose (Used for energy) in plants.
• What is the function of Plasmid DNA?

  Contains additional genes, often for antibiotic resistance that can be inherited.
• What is the function of a Flagellum?

  Movement.
• Give 3 adaptations for a sperm cell:

  Haploid Nucleus: Carries half the number of chromosomes (23) to combine with the egg's nucleus during fertilisation.

  Mitochondria: Provides energy for the sperm to swim to the egg.

  Tail: Propels the sperm towards the egg for fertilisation.
• Give 3 adaptations of an egg cell:

  - Haploid cell.

  - Contains a lot of nutrients in the cytoplasm.

  - the cell membrane changes structure right after fertilisation to prevent another sperm cell from entering.
• How are Ciliated Epithelial Cells specialised?

  - They are found on the surface of some organs.

  - They contain cilia (hair-like structures) at the top surface of the cell.

  - They move substances in one direction.
• What is a light microscope?

  A microscope that uses visible light to magnify and observe small objects or organisms.
• What is an electron microscope?

  Electron microscopes use a beam of electrons instead of light to achieve higher magnification and resolution.
• Eyepiece (Ocular Lens): Magnifies the image produced by the objective lens.
• Objective Lens: Magnifies the specimen; microscopes typically have multiple objective lenses with different magnification levels.
• Stage: Supports the slide or specimen being observed.
• Stage Clips: Holds the slide in place on the stage.
• Coarse Adjustment Knob: Used for initial focusing by moving the stage up or down.
• Fine Adjustment Knob: Allows precise focusing to obtain a clear image.
• Illuminator (Light Source): Provides light to illuminate the specimen.
• Diaphragm: Controls the amount of light passing through the specimen.
• Base: Provides stability and support for the microscope.
• Arm: Used to carry and support the microscope.
• What is magnification?

  The amount of times an image is magnified.
• Total magnification = magnification of objective lens x magnification of eyepiece lens
• magnification = image size/real size.

  
• What are enzymes?

  Biological catalysts that speed up a reaction.
• Active Site: The active site on the enzyme's surface binds with the substrate, providing a specific three-dimensional environment.
• Enzyme-Substrate Complex Formation: The substrate, a specific molecule, fits into the enzyme's active site, forming the enzyme-substrate complex for a precise interaction.
• Catalysis of Reaction: The enzyme catalyzes the conversion of the substrate into products once bound to the active site, lowering the activation energy.