Animal and Plant cells.
Animal + human cells.
- Cell membrane
- Perminant vacoule
- Cell wall
- Cell Membrane
Bacteria and Yeast cells.
- Cell wall
- Cell Membrane
- NO distinct nucleaus
- Ring of Plasmid DNA
- Chromosomal DNA
- Cell wall
- Cell membrane
Nucleaus: Controls all act activity in the cell (ANIMAL / PLANT / YEAST)
Cell Membrane: Controls the passage of substance in and out of cell (ANIMAL / PLANT / YEAST /BACTERIA)
Cytoplasm: Where chemical reactions take place (AMIMAL / PLANT /YEAST / BACTERIA)
Mitochondria: Produces energy for respiration (ANIMAL / PLANT / YEAST)
Ribosomes: Needed for protiensynthesis (ANIMAL /PLANT/ YEAST / BACTERIA)
Chloroplasts: Needed for photosynthesis (PLANT)
Vacoule: Filled with cell sap (PLANT / YEAST)
Cell wall: Strenghens the cell (PLANT/ YEAST / BACTERIA)
Chromosomal DNA: carries genetic infoamtion for cell / Plasmid: carries extra infomation (BACTERIA)
Flagella: Tail on the end of the cell - there is often muitiple (BACTERIA)
These are cells developped/ adapted to serve a specific purpose
Root hair cells ( To adsorb minerals + water in soil) : Long with a thin wall giving it a large surface area.
Sperm cells (Fertilise egg cell) : Head carries genetic material / infomaion as well as enzymes to penetrate the egg. ALSO the middle section is full of mitochondria to add speed this also benefits the tail.
Red blood cell (contains haemoglobin to carry oxygen to cells): outer membrane is thin to let oxygen diffuse quickly/ easily. Large surface area allows it to adsorb more oxygen. No nucleaus meaning cell is full of haemoglobin.
Leaf cell (adsorb light for photosynthesis): Filled with chloroplats. Regular shapes and closely packed cells form a continous layer to adsorb light.
- Dissolved substances travel by diffusion through the cell membrane.
- Diffusion is the spread of particles from an area of high concerntration to low concerntration in a net movement
- The greater the difference in concerntration the faster rate of reaction due to a steeper concerntration gradiant.
- Only smaller molecules can travel by diffusion, for example; amino acids and oxygen (which respires through diffusion)
- Occurs in Gases, liquids and solutions.
Enzymes are biological catalysts. There are optimum temperatures and pH values at which their activity is greatest. Enzymes are also proteins, and usually denatured above about 45ºC.
Enzymes are important in respiration. Aerobic respiration releases energy from glucose.
- PROTIENS --------------------------------> Protese
- FATS -------------------------------------> Lipase
- CARBOHYDRATES------------------------> Carbohydrase / Amylase
- Large molecular organisms develop systems for exchanging materials
- Cells differentate to serve different functions
- Specialised cells form tissues and some for structurres for organ
EXAMPLE OF TISSUE:
Muscular tissue: Can contract to cause movement (such as contraction and relaxing limbs)
Glandular tissue: Can produce and secrete substances (such as emzymes for chemical reactions)
Epithethial tissue: Covers the outside and inside of the organs (for example the stomach wall, gut and skin)
- Organ systems serve a specific purpose
- The digestive process needs a variation of enzymes to break food into soluble molecules
- Enzymes are produced by specialised cells in the glands and gut systems
The digestive system
In the mouth: Salvory glands produce amylase breaking down carbohydrates, the saliva also chews and moistens food into smaller balls and are swallowed
The oesopgagus: Is a tube that connects the mouth and the stomach to help move food along
In the stomach: Food is broken into smaller pieces by the stomach wall. Protese breaks the protiens into amino acids, Hydrochloric acid is also produced killing most bacteria and creating the correct PH for the protese enzymes.
The liver: Produces alkaline bile to neutralise the excess stomach acid (most enzymes can't work in such a high PH). The bile emulifies the fats/oils- making the digestion more efficant - the fats are therefore broken into smaller droplets.
The gall bladder:stores bile before released into the small intestine.
The pancreaus bland: produces digestive juices full of enzymes which are released into the small intestine
The small intestine: continues the process with the released digestive juices. Here the adsorbtion of soluble foods into the blood stream from the digestive system (excess foods are sent back to the pancreaus until its soluble)
In the large intestine: excess water is adsorbed from undigested foods
Stem: keeps the plant upright and carries nutrients to the leaves and around the plant. (IMPORTANT FOR: nutrition, exretion and growth)
Flower: contains organs for reproduction, attracts insects needed to carry the pollen between plants (IMPORTANT FOR: reproduction/pollination)
Leaf: allows photosynthesis to happen (IMPORTANT FOR: photosynthesis)
Roots: roots stabilise the plant, also adsorb water and nutrients to be carried through stem - to enhance growth (IMPORTANT FOR: growth and nutrients)
Inside a leaf.
Adaptations: Large surface area (Adsorbs more light) Chlorophyll (Adsorbs light to transfur energy into chemicals) Stomata (Lets Co2 diffuse into leaf) Thin (Short distance for co2 to diffuse into leaf) Network of viens (supports the transfur of light and carbohydrates)
Inside a leaf part 2.
Epidermis: allows more light to reach palisade cells
Wax cutitcle: acts as a layer of protection without blocking the light.
Palisade cells: adsorbs more light - chloroplasts in the palisade cells enhance this
Spongy layer: Air spaces allow Co2 to diffuse through the leaf and increases the surface area