Key concepts

• What is magnification?


  The number of times larger an image appears, compared with the size of the object.
• What is resolution?


  How clear an image is (smallest distance between two points that can be seen and not blurred into one)
• What are the parts of a microscope

  Eyepiece lens

  Arm

  Focus wheel

  Base

  Lamp

  Slide

  Stage

  Objective lenses

  
• What are the functions of parts of the microscope


  eyepiece lens - part of microscope you look through

  arm - handle for carrying, supports and connects the eyepiece to the base

  focus wheel - used to bring object in and out of focus

  base - supports the microscope

  lamp - provides light to illuminate specimen sometimes used as a mirror

  slide - a thin piece of glass that holds a specimen

  stage - a platform that holds the slide to look at

  objective lenses - many lenses with a range of different magnifications
• Why is an electron microscope better than a light microscope

  -achieve a higher resolution (clearer)

  -provides a higher magnification

  -more details can be seen and smaller things
• What are units and conversions?

  going from going from pm up mm

  mm down pm

  (x1000) millimetres (/1000)

  (x1000) mircrometres (/1000)

  (x1000) nanometers (/1000)

  (x1000) picometres (/1000)

  
• total magnification equation


  eyepiece lens mag x objective lens mag
• magnification equation


  Image size/actual size

  
• What is the field of view of a microscope?

  Everything you see when you look through the eyepiece

  
• PRAC Viewing cheek cells


  1) Take a clean cotton bud and stroke inside of your cheek gently

  2) Smear the cotton bud on the slide for a few seconds. Place the cotton bud in a beaker with disinfectant.

  3) Add methylene blue as a stain and place a coverslip

  4) Remove excess solution with tissue

  
• PRAC Viewing onion cells

  1) Remove a thin layer of cells from the onion piece that should be transparent and place it on the slide

  2) Add a drop of iodine solution as a stain

  3) Carefully place a coverslip on top

  4) Remove excess with a paper
• How to prepare a microscope slide

  To prepare a microscope slide you must:

  1) Apply a small thin layer of the cell ona slide

  2) Add a stain like iodine solution onto the slide - This will allow subcellular structures in the cell to be more noticeable

  3) Place a cover slip over the top of the cell - holds specimen in place, protects it from drying out and the environment.

  
• sub-cellular parts of an animal cell

  mitochondria - where respiration occurs to release energy

  cytoplasm - jelly substance where chemical reactions occur

  cell membrane - controls what goes in and out of the cell

  nucleus - holds the DNA controls the cell

  ribosome - where protein is made

  
• sub-cellular parts of a plant cell

  VACUOLE - stores cell sap

  mitochondria - where respiration occurs to release energy

  cell membrane - controls what goes in and out of the cell

  cytoplasm - jelly substance where chemical reactions occur

  nucleus - holds the DNA controls the cell

  ribosome - where protein is made

  CELL WALL - for structure and support

  CHLOROPLAST - absorbs sunlight for photosynthesis (food)

  
• What are Specialised cells

  cells designed for a particular purpose
• Sperm Cell info


  -to get towards the egg cell to fertilise

  -found in the testicles

  -haploid (one copy of each chromosmes-23)
• subcellular structures of sperm

  -STREAMLINED SHAPE

  -LARGE AMOUNTS OF MITOCHONDRIA - arranged in a spiral releases a lot of energy to power tail

  -FLAGELLUM - tail waves allowing it to swim

  -ACROSOME - a small vacuole that contains enzymes to break down substances in the egg cell to burrow inside

  -nuclues

  -cell membrane

  
• Egg cell info


  -to fertilise with the sperm cell

  -found in the ovaries

  -haploid (one copy of each chromosmes-23)
• subcellular structures of egg cell

  -JELLY COAT - protects, then hardens after fertilisation to only allow one sperm to enter

  -CYTOPLASM - packed with nutrients to supply the fertilised egg with energy and raw materials for the growth and development of embryo

  -haploid nucleus

  -CELL MEMBRANE - fuses with sperm cell membrane it is hard to stop more sperm

  
• Ciliated Epithelial Cell info

  -the cilia helps move the egg cell

  found in the oviduct

  -diploid (two sets of chromosomes-46)
• subcellular structures of Ciliated Epithelial Cell

  -CILIA - covered in cell membrane, can contract and cause wavy movements, moves egg to uterus

  -MITOCHONDRIA - needs a lot of energy to move the egg cell

  -nucleus

  
• subcellular structures of Bacterial cells

  -FLAGELLUM - used for locomotion/movement/mobility (some have none, one or many)

  -FLEXIBLE CELL WALL - for support not made out of cellulose

  -CHROMOSOMAL DNA - coiled cluster, loose DNA

  -PLASMID DNA - reproduced independently and can be transferred to other cells

  -cytoplasm - contains smaller ribosomes

  -cell membrane

  
• What is a eukaryotic cell?

  cell that has a nucleus
• What is a prokaryotic cell?


  A cell that has no nucleus
• How do bacterial reproduce?

  asexually
• What is the first type of cells in a developing embryo

  stem cells, they differentiate- develop specialised structures or functions
• What are enzymes

  they are biological catalysts, a substance found in living organisms that speed up a reaction and are proteins

  
• What are digestive enzymes

  Produced by specialised cells in the pancreas and digestive tract . They pass out of the cells into the stomach and small intestines. They breakdown larger molecules into simpler compounds that are easily absorbed.
• What is the enzyme that breaks down the substrate strarch and where is it produced

  carbohydrase and produced in the mouth as saliva, pancreas and small intestines.
• What substrate/reactant does the enzyme lipase act on

  lipids (fats)
• Where is lipase found

  Pancreas and small intestine
• What is the enzyme that breaks down the substrate protein and where is it produced

  protease and produced in pancreas, small intestines and stomach
• What product is made from carbohydrase and starch

  sugar/glucose
• What product is made from lipase and lipids

  fatty acids and glycerol
• What products is made from protease and protein

  amino acids

  
• What creates different types of enzymes


  the differrent sequences and type of amino acid can change function and shape of an enzymes
• What are enzymes so specific about

  which reaction they speed up as only the right shaped substrate it will bind and react
• Where does the enzyme bind with the substrate

  active sit - it has a specific shape
• what is the lock and key hypothesis

  A theory that describes how substrates must be the correct shape to fit the active site of an enzyme. enzyme is the lock and the substrate is the key

  
• What are the Enzyme Action Steps

  1. Substrate binds to enzyme's specific active site, it is complementary (lock and key)

  2.When joined a enzyme-substrate complex is formed

  3. The enzyme causes a chemical reaction, the substrate breaks down into products

  4. Product is released from enzyme, the enzyme is free to be used again

  (steps can be done both ways)