Chapter One: Flashcards
Who made the first ever Microscope?
Hans and Zacharias Janssen in the 1590s
What magnification are modern light microscopes capable of?
1500x
What magnification are electron microscopes capable of?
2000000x (2 million times)
What do both types of microscope use to function?
Radiation
What is Resolution?
The ability to distinguish two objects from each other
What does Resolution depend on?
The distance between two distinguishable points.
What type of microscope has higher resolution?
Electron Microscope
Formula for Length of object?
Length of magnified object / magnification
Formula for Length of magnified object?
Length of object * magnification
Formula for Magnification?
Length of magnified object / length of object
What limits a light telescope’s magnification?
Its Wavelength
What do electron microscopes use to form an image?
Beams of electrons
What do light microscopes use to form an image?
Rays of light
Name the parts of a standard microscope:
Eyepiece Objective Lens 1000x objective Disc diaphragm Illuminator Fine Focus Coarse Focus Arm
What is the formula for total magnification?
Power of ocular lens * power of objective lens
What is the formula for power of ocular lens?
Total magnification / power of objective lens
What is the formula for power of objective lens?
Total magnification / power of ocular lens
If the prefix is tera(T), what is the scientific notation and multiplying factor?
Multiplying factor: 1000000000000 (trillion)
Scientific Notation: 10^12
If the scientific notation is 10^9, what is the prefix and multiplying factor?
Prefix: Giga(g)
Multiplying Factor: 1000000000 (billion)
If the multiplying factor is 1000000(million), then what is the prefix and scientific notation?
Prefix: Mega(M)
Scientific Notation: 10^6
If the prefix is kilo(k), what is the scientific notation and multiplying factor?
Multiplying Factor: 1000
Scientific Notation: 10^3
If the scientific notation is 10^-3, what is the prefix and multiplying factor?
Prefix: Milli (m)
Multiplying Factor: 0.001
If the multiplying factor is 0.000001(millionth), what is the prefix and scientific notation?
Prefix: Micro (µ)
Scientific Notation: 10^-6
If the prefix is nano(n), what is the scientific notation and multiplying factor?
Multiplying Factor: 0.000000001 (billionth)
Scientific Notation: 10^-9
If the scientific notation is 10^-12, what is the prefix and multiplying factor?
Prefix: Pico (p)
Multiplying Factor: 00.000000000001(trillionth)
Name all organelles of a plant and an animal cell:
Cell Membrane Cell Wall Chloroplasts Cytoplasm Mitochondria Nucleus Ribosomes Vacuole
What Organelle is unique to an Animal cell?
Mitochondria
What Organelles are unique to a plant cell?
Cell Wall
Chloroplasts
Vacuole
What is the function of the Nucleus?
Contains Genetic Information, controls cell activities
What is the function of the Cytoplasm?
Most chemical processes take place here, controlled by enzymes
What is the function of the Cell Membrane?
Controls movement of substances into and out of the cell
What is the function of the Mitochondria?
Where most energy is released by respiration
What is the function of the Ribosomes?
Where protein synthesis takes place
What is the function of the Cell Wall?
Strengthens the cell
What is the function of Chloroplasts?
Contains Chlorophyll, where photosynthesis takes place
What is the function of the Vacuole?
Filled with cell sap to keep the cell turgid
Name five specialised cells:
Leaf Cell Root Hair cell Sperm Cell Red Blood Cells Egg Cell
What is the purpose of a Leaf Cell?
Absorbs light energy for Photosynthesis
What are the properties of a Leaf Cell?
Packed with Chloroplasts
Regular Shaped, closely packed together to form continuous layer for efficient sunlight absorption
What is the purpose of a Root Hair Cell?
Absorbs water and mineral ions from soil.
What are the properties of a Root Hair Cell?
Long ‘finger-like’ process within a very thin wall, which gives large surface area
What is the purpose of a Sperm Cell?
Fertilises the Egg Cell (Ovum)
What are the properties of a Sperm Cell?
Head contains genetic information and an enzyme to help penetrate the Egg Cell’s membrane.
Middle section packed with mitochondria for energy
What is the purpose of a Red Blood Cell?
Contains Haemoglobin to carry oxygen to cells
What are the properties of a Red Blood Cell?
Thin outer membrane to let oxygen diffuse easily
Shape increases surface area
No nucleus, the whole cell is full of Haemoglobin
What are the properties of an Egg Cell (ovum)?
One of the largest cells in the human body
Haploid Nucleus - contains half the number of chromosomes - and a large cytoplasm contains nutrients and mitochondria needed for Mitosis.
What Organelles are in a Bacteria Cell?
Cell Wall Cytoplasm Large Circular DNA Pili Plasmids Ribosomes
What is the function of the Plasmids?
Contains genes that help cell function
What is a Prokaryotic Cell?
Cells that don’t have a membrane-bound nucleus meaning their DNA is free in the cytoplasm
Give an example of a Prokaryotic Cell:
Bacteria Cell
What is the function of the Pili?
Allows Bacteria cells to exchange plasmids
What is a Eukaryotic Cell?
Cells that have a membrane-bound nucleus
Have linear chromosomes instead of circular
Give three examples of Eukaryotic Cells:
Animal Cell
Plant Cell
Fungus Cell
What type of Catalysts are Enzymes?
Biological Catalysts
What is a Catalyst?
a substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change
What are Enzymes?
Proteins folded into complex shapes
What do the complex shape of Enzymes allow?
Smaller molecules to fit into them
Where do substrate molecules fit into the enzyme?
At its Active Site
What may happen if the shape of an enzyme changes?
The active site may no longer work. We say that enzyme has denatured.
How can enzymes be denatured?
High temperatures or extreme pHs
Name three enzymes that catalyse the breakdown of food molecules:
Amylase
Protease
Lipase
What reaction is Amylase the catalyst for?
Starch -> Sugar
What reaction is Protease the catalyst for?
Proteins -> Amino Acids
What reaction is Lipase the catalyst for?
Lipids -> Fatty acids + glycerol
What is Amylase an example of?
A carbohydrase.
Where is Amylase produced?
Salivary Glands, pancreas, small intestine
Where is Protease produced?
Stomach, pancreas, small intestine
Where is Lipase produced?
Pancreas, small intestine
Why is catalysis by enzymes important for life processes?
Speeds up reaction times
What is the test for Starch?
Add iodine solution to substance
If it turns black-blue starch is present.
What is the test for Glucose?
Dissolve substance into water and adding benedict’s solution
If it turns blue Glucose is present
What is the test for Proteins?
Use Biuret regent
Turns mauve/purple if protein is present
What is the test for Lipids?
Use the emulsion test
Mix the substance with 2ml of Ethanol and an equal volume of distilled water
A milky white emulsion is formed if lipids are present.
What is a calorimeter?
A piece of equipment designed to measure the energy released or absorbed during a chemical reaction
What is the lock and key theory?
The enzyme being the lock and the substance being the key. Only the correct sized substance fits into the keyhole (the active site)
What does the shape of an enzyme depend on?
The order of amino acids
What temperature do enzymes work best at?
37 degrees celsius
What is the formula for Enzyme activity?
rate * reaction volume
What is Diffusion?
When particles move from a region of high concentration to a region of low concentration.
When does Diffusion happen?
When particles are free to move
What is the purpose of Diffusion?
For dissolved substances to pass through the cell membrane to get in or out of a cell.
What is Osmosis?
The movement of water from a region of low concentration to a region of high concentration
What do you need for Osmosis to happen?
- Two solutions with different concentrations
- A partially permeable membrane to separate them
What is the purpose of Osmosis?
Allows water to move across cell membranes
