Topic 1- Key Concepts In Biology Flashcards
What’s a prokaryotic cell? Example…
A small simple cell
Bacterium
What’s a eukaryotic cell? Example
Complex cell.
Plant or animal
In which cubcellular structure do most reactions for respiration take place? ( plant)
Mitochondria
Which sub cellular structure maintains the internal pressure of a plant cell?
Vacuole
Similarities and differences between a plant and bacteria cell…
Similarities - both have a cell membrane, cell wall, cytoplasm and ribosomes
Differences- plant cells have chloroplasts and mitochondria but bacteria cells don’t.
Chromosomes of plant cells are contained within the nucleus, however a bacteria’s dna floats freely in the cytoplasm. Bacteria cells have small loops of dna called plasmids.
A- cell membrane, holds cell together and controls what enters or leaves
B- nucleus, contains genetic material that controls activities of the cell
C- ribosome, involved in translation of genetic material and protein synthesis
What’s a ciliated epithelial cells main function?
To move bacteria in one direction
Where are ciliated epithical cells found ?
On the surface of organs
Two functions of an egg cell….
To carry female dna
Provide nutrients to the embryo in its early stages
Why do sperm cells contain a large number of mitochondria?
To provide energy ( from respiration) that the egg needs to swim
Why is it important egg and sperm cells are haploid ?
So when the nucleuses combine at fertilisation the resulting cell with have the right number of chromosomes.
How are ciliated epithecal cells adapted for moving substances?
They have cilia, which beat to move substances in one direction across the surface
Why does the structure of an eggs cell membrane change after fertilisation?
To stop any more sperm getting in and making sure the offspring has the correct amount of dna.
A - the tail, this allows the sperm to swim towards an egg cell
B- acrosome, stores enzymes the sperm needs to digest its way through the membrane off an egg cell
What’s the purpose of the fine adjustment knob on a light microscope?
Focus the lens untill a clear image of what’s on the slide appears
What has a higher resolution and magnification, electron microscopes or light microscopes?
Electron microscopes have both a higher resolution and magnification
How would you put a cover slip onto a specimen on a slide so it’s ready to be viewed under a light microscope ?
Cover slip should be placed at one end of the specimen and put on a mountain needle before being pressed down, ensuring theirs no trapped air left under.
How has electron microscopy increased our knowledge of cells?
Higher resolution and magnification has allowed biologists to see very small structures in cells.for example, internal structures of mitochondria and chloroplasts
Labels of important features
Magnification and scale used
How to calculate magnification of a microscope?
Magnification of microscope = Magnification of eyepiece X magnification of objective
How do you calculate magnification of an image ?
Magnification of image = size of image divided by size of real onject
Is a picometer larger or smaller than a nanometr?
A picometer is smaller than a nanometer. Picometer ( 10^-12) Nanometer (10^-9)
Key parts of an animal cell..
Nucleus- stores dna
Cell membrane - controls what enters and exits cell
Mitochondria- respiration , how the cell produces energy
Ribosomes - to make essential proteins for the cell
Cytoplasm- where chemical reactions happen
3 extra parts to a plant cell and their functions ..
Cell wall- gives the cell extra strength and protection
Vacuole- store cell sap
Chloroplasts - for photosynthesis ( plant making energy cell from sunlight )
Parts of a bacterial cell..
Where’s its dna located?
Flagellum
Ribosomes
Cell membrane
Cytoplasm
DNA floats in the cytoplasm
Is in the plasmid loops
2 categories of cells
Features
Example of each
Prokaryotic -smaller,simpler, no nucleus (bacteria)
Eukaryotic -bigger, complex,have a nucleus (plant and animal )
2 specialised cells
Sperm
Egg
Are sperm and egg cells haploid or diploids and why?
Sperm and egg cells are haploid (23 chromosomes )
So when they fuse together they have the full number of chromosomes
2 features in a sperm cell
Functions of the features
Acrcsome- filled with enzymes to break down the egg cell
Mitochondria - gives it energy to reach the egg cell
What’s the ciliates epithelial cell?
And hows it specialised ?
A specialised cell that’s adapted to have cilia
Often on organs
Cilia sway to move nutrients along
Features of a light microscope …
Can view living cells
Low resolution
1590s
Features of electron microscopes ..
1930 s
Higher resolution
Cannot view living cells
How to find total magnification ?
First do magnification of eyepiece lens X magnification of objective lens
Them do image size /real size
What are enzymes ?
Biological catalysts ( speed up reactions )
What’s the substrate
The thing the enzyme is reacting with
What’s synthesis ?
Joining smaller molecules together to form. Bigger ones
Why can an enzyme denature
Bad ph or temperature
How can we also increase enzyme activity
Increasing substrate concentration
This will increase enzyme activity until all the active sites become full
How do we test reducing sugars
Do the Benedict’s reagent test
Steps of Benedict’s reagents test for reducing sugars
- Add Benedict’s reagent to sample
- Heat gently with water bath
- Positive = coloured precipitate
Blue colour = low sugar concentration
Orange / red colour = high sugar concentration
How does the structure of an artery differ from the structure of a vein ?
Thicker walls
More elastic tisssue
Smaller lumen
No valves, but veins have valves
What is a catalyst ?
A substance which increase the speed of a reaction , without being changed or used up.
Why do enzymes only work for one substrate?
Because they have a specificity shaped active site for the substrate to fit into.
What’s the lock and key theory?
The substrate fits into the enzyme just like a key fits into a lock
What happens as you increase the temperature of an enzyme - catalysed reaction?
What happens if it get too hot ?
-The temperature increases the rate at first.
-If it gets too hot,the bonds holding together the enzyme break . This changes the shape of the enzymes active site and denatures it
How does a too high or too low ph affect enzymes ?
-interferes with the bonds holding the enzyme together. This changes the active sites shape and denatures the enzymes
What happens to the rate of reaction is we increase the substrate concentration?
The reaction will speed up because an enzyme is more likely to meet up and react with a substrate molecule
Only true up to a certain point
What is a prokaryote?
Eukaryote?
Prokaryote- a prokaryotic cell
Eukaryote- eukaryotic cell
What is a prokaryote?
Eukaryote?
Prokaryote- a prokaryotic cell
Eukaryote- eukaryotic cell
What’s a ribosome?
Involved in translation of genetic material in the synthesis of proteins.
