Topic 1 Key Conscepts In Biology Flashcards
What makes cells specialised?
Cells have a structure which makes them assorted to their function
What are the functions of an egg cell?
To carry female dna and nourish the developing embryo in the early stages
How is an egg adapted to its function?
1) contains nutrients in the cytoplasm to feed the embryo
2) has a haploid nucleus
3) after fertilisation its membrane changes its structure to stop any more sperm getting in
Why does an eggs membrane change its structure?
1) So that the offspring had the right amount of DNA
2) Stops any sperm getting in
What’s the function of a sperm?
Transports the males DNA to the females egg
How ha she sperm adapted to its function?
1) has a long tail to swim to the egg
2) has a lot of mitochondria in the middle section to provide energy to swim
3) has an acrosome at the front of the head to digest its way through the membrane egg cell
4) has a haploid nucleus
What does the sperm produce at the head?
Enzymes to digest through the eggs membrane
What are cilliated epethelial cells specialised for?
Moving materials
What’s the epithelial cells main features?
1) have hair like structures on the top surface of the cell
2) they line the surface of organs
What’s is epetherial cells functions?
To move substances in one direction along the surface of the tissue
What is resolution?
Resolution means how well a microscope distinguishes between two points that are close together
What does it mean if something has a higher resolution?
Where an image can be seen clearly and in more detail
How do light microscopes work?
They work by passing light through the specimen. Can use them to see living cells
How do electron microscopes work?
They use electrons rather than light. Higher magnification and resolution
How is an electron microscope different to a light microscope
Lets us see in more detail like internal structure. Allows a greater understanding of how cells work and the role of sub cellular structures
What is an enzyme?
Are catalysts produced by living things
What is a substrate?
Molecule changed in the reaction
Molecule that changes in the reaction
What is an active site?
Is a part where it joins the enzyme to the substrate
How does a catalyst reaction work?
The substrate has to fit into the enzyme
What is the terminology used when the substrate fits into the the enzyme?
Lock and key method
How does an enzyme and substrate denature?
If it is too hot, the bonds holding the active site and substrate break, causing the substrate to change shape. This denatures it
How can the pH effect an enzyme?
If it’s too high or too low the pH interferes with the bonds holding the enzyme together. Changes the shape of the substrate and denatures it
How can the substrate concentration effect the enzyme activity?
It effects the rate of reaction. If the concentration is high there is a faster reaction. Because it is more likely to meet up and react with the substrate molecule
What is diffusion?
The gradual movement of particles from a higher concentration to a lower concentration (from somewhere where there’s lots of it to not much)overall
