Variety of Organisms Flashcards
Define Diffusion :
Net movement of particles from an area of high concentration to an area of low concentration
Define Osmosis :
Net movement of water molecules across a semi permeable membrane from an area of high to low concentration
Define Active Transport :
Movement of particles against a concentration gradient (area of low to high concentration) using energy released during respiration
Characteristics of living organisms :
- Nutrition
- Respire
- Excrete
- Respond to surroundings
- Movement
- Control internal conditions
- Reproduce
- Grow and develop
What organelles are found in Plant Cells and what are their functions?
- Chloroplasts- photosynthesis
- Cell wall- Support structure
- Vacuole- Support call
- Ribosomes- Proteins made
- Mitochondria- Reactions for aerobic respiration take place
- Cytoplasm- Chemical reactions happen
- Cell Membrane- Control what goes in & out
- Nucleus- Contain genetic material
What organelles are found in Animal Cell and what are their functions?
- Ribosomes- Proteins made
- Mitochondria- Reactions for aerobic respiration take place
- Cytoplasm- Chemical reactions happen
- Cell Membrane- Control what goes in & out
- Nucleus- Contain genetic material
Define a Catalyst :
A substance which increases the speed of a reaction without being changed or used up in the reaction
How can Temperature and pH affect Enzyme function?
- Higher temperature increases rate, enzymes and substrate have more energy so move more and collide = enzyme-substrate complexes
- If too hot - bonds holding enzyme together break, changing shape of active site, substrate won’t fit = enzyme denatured
What is a Substrate?
Molecule that is changed in a reaction
What is an Active Site?
Part where a substrate joins on to the enzyme
What is a ‘Lock and Key’ model?
Substrate fits into the enzyme just like a key fits into a lock
Describe a Protoctists and give an example:
- Single-celled, microscopic
- Some like plant cells and others like animal cells
- E.g. Chlorella (Plant), Amoeba (animal)
Describe a Bacteria and give an example:
- Single-celled, microscopic
- No nucleus
- Circular chromosome of DNA
- Feed off other organisms
- Some can photosynthesise
- E.g. Lactobacillus bulgaricus
Describe a Virus and give an example:
- Particles, very small
- Reproduce inside living cells
- Infect all types of living organisms
- Loads of different shapes and sizes
- No cellular structure
- E.g.HIV, Tobacco mosaic virus
What are Pathogens?
- Organisms that cause disease
* E.g. Fungi, Bacteria, Virus, protoctists
