Section 1 - The nature and variety of living organisms Flashcards
MRS GREN
- Movement
- Respiration
- Sensitivity
- Growth
- Reproduction
- Excretion
- Nutrition
Levels of organisation
- Organelle
- Cell
- Tissue
- Organs
- Organ Systems
Animal characteristics
- Eukaryotic
- multicellular
- nervous coordination
- store carbohydrates as glycogen
Plants characteristics
- Eukaryotic
- Multicellular
- Have chloroplast for photosynthesis
- Cell walls made of cellulose
- Store carbohydrates as starch/sucrose
Fungi characteristics
- Some single-celled (yeast)
- Some have body called mycelium, made up of hyphae that contain lots of nuclei
- cell walls made of chitin
- store carbohydrates as glycogen
Animal nutrition
heterotrophic
Plant nutrition
Autotrophic
Fungi nutrition
Saprotrophic - release extracellular enzymes to dissolve their food + absorve nutrients
Protoctists characteristics
- Eukaryotic
- Single-celled
- Some chloroplasts
- Chlorella (plants-like)
- Amoeba (animal-like)
Bacteria characteristics
- Prokaryotic
- single-celled
- dont have nucleus
- DNA in circular chromosomes
- Some photosynthesise
Viruses Characteristics
- smaller than bacteria
- Only reproduce inside living cells
- Inflect all type of organims
- Have a protein coat around genetic material (DNA or RNA)
Organisms that are pathogens
- Fungi
- Protoctists
- Bacteria
- Viruses
enzyme def
- biological catalysts produced by living things, usually make a reaction happen more quickly.
- They are proteins that are made up of chains of amino acids
Catalyst def
Substance which increases speed of a reaction without being changed or used up in the reaction
explain lock & key model
- Enzymes normally speed one reaction
- Because to work, substrate has to be the correct shape to fit the active site of the enzyme
Factors affecting enzyme function
- pH
- Temperature
enzyme pH
- pH interferes with the bonds that hold the enzyme together
- Optimum pH 7 but not always
- If too high changes the shape of the active site and denatures the enzyme
enzyme temperature
- high temp increases the rate. Enzyme and active site move more quickly + more likely to collide
- If too hot bonds holding enzyme together break + change active site. Denatures the enzyme
Diffusion def
Net movementof particles from area of higher concentration to area of lower concentration
Diffusion characteristics
- Passive process - dosent require energy
- Both liquids and gases use it
-The bigger the difference in concentration, the faster the diffusion rate
Diffusion in cell membranes
YES
small molecules like: glucose, amino acids, water and oxygen
NO
Big molecules like: starch, proteins
Osmosis def
net movement of water molecules across a partially permeable membrane from a region of high water concentration to a region of low water concentration
Active transport def
Movement of particles against concentration gradient using energy released during respiration
Four factors that affect movement of substances
- surface area to volume ratio
- distance
- temperature
- concentration gradient
