Movement Of Substances and DNA Flashcards
Diffusion definition
The net random movement of particles from an area of high concentration to an area of low concentration, as a consequence of the random movement of individual particles.
Rate of diffusion factors
- Distance travelled
- Concentration gradient
- Temperature
- Surface area/volume ratio
Osmosis definition
The net random movement of water from an area of high water potential to an area of low water potential across a partially permeable membrane.
What happens for animal and plant cells in a Hypotonic solution?
Animal cell -
Water enters the cell, because there is more water potential outside the cell, and the cell bursts, in state of lysis.
Plant cell -
Water enters the cell and it would plump up, in state of turgid.
What happens to animal and plant cells in a Hypertonic solution?
Animal cell -
There is less water potential outside the cell, so water escapes, making the cell shrivel up in state of crenated.
Plant cell -
Water escapes and the cell membrane is pulled away from the cell wall, making the cell soft, plasmolysed
Active transport definition
The movement of dissolved molecules into and of a cell, against the concentration gradient i.e. From low to high.
What is needed for active transport?
ATP energy
Carrier proteins in the cell membrane.
Mitosis
Normal body cells (i.e. Anything but sex cells) divide by mitosis.
Gene
A gene is a section of a chromosome, which codes for a particular characteristic by a protein.
Chromosome
DNA in the nucleus is arranged into 46 long coiled molecules called chromosomes. Chromosomes are composed of DNA and proteins.
