Structure and Functions in Living Organisms Flashcards
Level of organisation
Cells, Tissues, Organs, Organ System
- A cell is a group of organelles working together to perform the same function
- A tissue is a group of cells working together to perform the same function
- An organ is a group of tissues working together to perform the same function
- An organ system is a group of organs working together to perform the same function
What elements are found in carbohydrates (glucose)+ how to test for it
- Carbon, Hydrogen and Oxygen
- Heat solution in water and add Benedict’s solution, turns from blue to:
- green or yellow in low concentration
- brick red in high concentration
What elements are found in protein + how to test for it
- Carbon, Hydrogen, Oxygen and Nitrogen
- Add biuret solution, turns from blue to purple
What elements are found in lipids + how to test for it
- Carbon, Hydrogen and Oxygen
- Add ethanol + water to the solution and shake, if positive test a milky white emulsion forms
What is starch made up of and how to test for it
- Made up of simple sugars (glucose) joint together
- Add iodine solution, if positive test the sample should turn blue-black
What are enzymes
- Biological catalysts
- Which speed up the rate of reaction without being used up
What is metabolism
It’s the rate at which chemical reactions take place in the body
What’s an active site
An area of an enzyme where substrate attaches
What is diffusion
- net movement of particles
- from area of high concentration to an area of low concentration
The effect of too high temperature on enzyme activity + the effects of too high or too low pH on enzyme activity
- Decreases activity
- Enzyme denatures and substrate can no longer fit the active site
What are the factors affecting diffusion
- Temperature
- Concentration gradient
- Surface area to volume ratio
- Distance
What is osmosis
- net movement of water molecules
- across a partially permeable membrane
- from area of high water conc. to area of lower water conc.
What is active transport
- net movement of particles
- from area of low concentration to an area of high concentration
- requiring energy
What’s a limiting factor
- Factor in a reaction which is in the shortest supply
- Lack of this factor is the reason why the rate of reaction no longer increases
What is the process of photosynthesis
- Photosynthesis is the process where plants make their own ‘food’ (the food it produces is glucose)
- Chloroplast contains chlorophyll which absorbs sunlight and uses the energy to convert CO2 and H2O into glucose and water
Why is rate of photosynthesis low in the morning
- Carbon dioxide levels are high
- Temperature is a limiting factor
- Low temperature inhibits enzyme activity
Why is rate of photosynthesis high at midday
- High temp maximises enzyme activity
- Carbon dioxide is a limiting factor as it is in the shortest supply
Whats magnesium needed for in plants
- Needed to produce chlorophyll in plants
- Not enough leads to leaves yellowing
Whats nitrogen needed for in plants
- Nitrates = source of nitrogen which is needed to make amino acids for protein
- Not enough causes stunted growth and yellowing of leaves
What’s contained in the top half of a leaf + their functions
- Waxy Cuticle: Prevent evapouration of water
- Upper epidermis: Transparent to allow light to enter leaf
- Palisade Mesophyll: Contains lots of chloroplast for photosynthesis
What’s contained in the bottom half of a leaf + their functions
- Spongy mesophyll air spaces: Allows gases to diffuse
- Xylem: Allows entry of water into leaf by tranpiration stream
- Phloem: Takes away glucose produced from photosynthesis
- Guard cells: Controls opening and closing of stomata
- Stomata: Allows CO2 to enter the leaf
How is a leafs structure better adapted for photosynthesis
- Thin; so gases don’t have to diffuse far
- Large surface area; so it can absorb more light
Carbohydrates
source + function
- Pasta, rice
- Provides energy
Proteins
source + function
- Meat
- Important for growth and repair of muscles
Lipids / Fats
source + function
- Butter
- Provides energy + provides insulation
Vitamins A, C and D
source + function
A:
* Liver
* Helps improve vision
C:
* Oranges
* Helps to prevent scurvy
D:
* Eggs
* Needed for strong bones
LOE
Mineral Ions
Calcium + Iron
source + function
Calcium:
* Milk
* Needed to make strong teeth + bones
Iron:
* Red meats
* Needed to make haemoglobin for healthy blood
Fibre
source + function
- Fruits + Vegetables
- Aids movement of food through gut
Water
function
- Constant supply to replaces water loss from sweating, urinating, breathing