Chapter 1 Flashcards
Describe the differences and give examples of prokaryotic and eukaryotic cells?
Eukaryotic cells are complex, these include animal and plant cells. Prokaryotic cells are smaller and simpler (a single- celled organism),these include bacteria cells.
Talk about the nucleus
Contains genetic material that controls the activity of the cell. The genetic material is arranged into chromosomes.
Talk about the cytoplasm
Gel like substance where most of the chemical reactions happen. It contains enzymes that control these chemical reactions.
Talk about cell membrane
Holds the cell together and controls what goes in and out of the cell.
talk about the ribosomes
This is where protein synthesis happens
Talk about the mitochondria
This is where most of the reactions for aerobic respiration takes place. Respiration transfers energy that the cell needs to work.
Talk about the cell wall
This is rigid and made of cellulose. It supports and strengthens the cell.
Talk about the vacuole
Contains cell sap ( a weak solution of sugar and salts) It maintains internal pressure to support the cell
Talk about chloroplasts
This is where photosynthesis takes place. They contain a green substance called chlorophyll.
What subcellular structures does a bacteria cell have
Chromosomal DNA, Ribosomes, cell membrane, plasmid dna, flagellum
Talk about chromosomal DNA
It controls the cells activities and replication, it floats free in the cytoplasm
Talk about Plasmid DNA
They are small loops of extra dna that aren’t part of the chromosome. Plasmid contains genes for things like drug resistance and can be passed between bacteria.
Talk about the flagellum
A long hair like structure that rotates to make the bacterium move. It can be used to move the bacterium away from harmful substances like toxins and towards beneficial things like oxygen or nutrients.
Describe egg cells
It contains nutrients in the cytoplasm to feed the embryo. It has a haploid nucleus. Straight after fertilisation its membrane changes structure to stop any more sperm from getting in. This is to make sure the offspring ends up with the right amount of DNA
Describe sperm cells
The function of the sperm cell is to transport the males dna to the females egg. A sperm has a long tail so it can swim to the egg. It has lots of mitochondria in the middle section to provide energy needed to swim. It has an acrosome in the front of its head where it stores enzymes needed to digest its way through the membrane of the egg cell. It also contains a haploid nucleus.
Describe ciliated epithelial cells
They line the surface of organs. Some of them have cilia (hair like structures) on the top surface of the cell. The function of the cell is to move substances in one direction across the surface of the tissue eg. move mucus
What is resolution
How well you can distinguish two points that are close together. A higher resolution means you can see the image more clearly and in more detail.
PRACTICAL: How to use a microscope ( Include making a slide and using the microscope)
Cut a thin slice of epidermal tissue (it needs to be thin to let light pass through it).
Take a clean slide and use a pipette to put one drop of water in the middle of it, this will secure the specimen in place.
Then use tweezers to place the specimen on the slide.
Add a stain (eg iodine) this makes the specimen easier to see.
Place a cover slip over the specimen holding it at an angle.
Press it down gently so that there are no air bubbles.
Then clip the slide onto the stage.
Select the lowest powered objective lens.
Use the coarse adjustment knob to move the stage up, then look down the eyepiece and move the stage downwards until the specimen is in focus.
Adjust the focus with the fine adjustment knob until the image is clear.
If you need to see more, increase magnification with a higher powered objective lens.
Name all of the parts of a microscope
Eyepiece lens, coarse adjustment knob, fine adjustment knob, stage, lamp/ mirror, objective lenses, clip
Both Formulas for magnification
Magnification = eyepiece lens magnification x objective lens magnification.
Magnification = image size/ actual size.
I
A M
Units and how to covert them for microscopy
x 1000 going down
millimetre
micrometer
nanometer
picometer
What factors affect the rate of reaction of enzymes
Temperature
Ph
substrate concentration
What are enzymes
Biological catalysts which speed up the rate of a reaction without being changed or used up
how to calculate the rate of an enzyme reaction
rate = change/time
What does carbohydrase do
convert carbohydrates into simple sugars
What does protease do
breaks down proteins into amino acids
What do lipases do
Convert lipids into fatty acids and glycerol
How do you test for sugars
Using benedict’s solution
Add benedict regent (blue) to a 5cmcubed sample and heat in a water bath at 75’C
If sugars are present the colour will change to brick red
How do you test for proteins
Biuret test
add a few drops of potassium hydroxide to make the solution alkaline
then add copper sulfate solution which is blue
If protein is present, the solution will turn purple
How do you test for lipids
Emulsion test
shake the test substance with ethanol for a minute until it dissolves and put the solution into distilled water
if lipids are present, they will precipitate and show up as a milky colour
How do you test for startch
iodine
add iodine to the test sample
if iodine is present, it will change from orange/brown to blue-black colour
How do you calculate the energy in food
mass of water x temp change x 4.2
How do you calculate the energy in food
mass of water x temp change x 4.2
How do you calculate the energy per gram of food
energy in food/mass of food
What is diffusion
Movement of particles from an area of higher concentration to an area of lower concentration
What is active transport
Movement of particles across a membrane from an area of low concentration to an area of high concentration across a partially permeable membrane
What is osmosis
Movement of water molecules across a partially permeable membrane from a region of higher water concentration to an area of lower water concentration
where are amalyse, protease and lipase made
amylase
-pancreas
-small intestine
-salivary glands
protease
-pancreas
-small intestine
-stomach
lipase
-pancreas
-small intestine
