Enzymes And Eurkaryotic And Prokatyotic Cells Flashcards
What is metabolism?
The sum of thousand of biochemical reactions.
A single chain is called a metabolic pathway.
What would happen without enzymes?
Take place very slowly
Enzymes are biological catalysts
How to enzymes act as a catalyst?
Require an input of energy.
The input energy is called activation energy, a reaction that needs a high activation energy can’t start at a low temperature
Enzymes reduce the active energy
Enzymes are also….
Globular proteins and can’t be involved in breaking down molecules or building molecules.
E.g. Digestive systems and DNA REPLICATIOON
How does the enzyme use is active site?
A substance that’s acted upon by an enzyme is called a substrate.
The active site is a region on the surface of the enzyme molecule where a substrate molecule can attach its self. This is where a catalysed reaction takes place.
The shape of the substrate molecule and the shape of the active site are complementary.
As soon as the enzyme substrate complex has formed, the product of the reaction is released and enzyme is ready to accept another substrate molecule
Why are enzymes specific?
Catalysed one Specific chemical reaction
Substrate must be the right shape to fit into the active site.
Only one substrate will be the correct shape to fit
Anything that changes the shape of the active site will affect how well the enzyme works
What is the effect of temperature on enzymes?
As temp increases, enzyme reactions become faster because the molecules have more energy.
However, at high temperatures the atoms of the enzyme molecule vibrate more rapidly and break the weak bonds that hold the tertiary structure together. The shape of the active site chances and the substrate can not longer fit in.
The effect of PH on enzyme activity
Acids and alkalis can denature enzymes
Hydrogen ions in acids and hydroxyl ions in alkalis disrupt the weak bonds and change the shape of the active site
4 organelles animals and plant cells have in common
Nucleus contains the genetic material that controls what the cell does
Cytoplasm contains enzymes that speed up biochemical reactions
Cell surface membrane hold the cell together and contains what goes in and out
Mitochondria are where glucose and oxygen are used in respiration to prove a source of energy for the cell
What are the 3 organelles that only plants have?
Rigid cell wall made of cellulose gives the cell support
Vacuole contains cell sap a weak solution of sugar and salts
Chloroplasts control chlorophyll for photosynthesis
Prokaryotic bacterial cell features
Roughly a tenth the size of eukaryotic cells
Cells don’t contain a nucleus mitochondria and chloroplasts
They don’t have a nucleus, there DNA floats freely in the cytoplasm, some also have rings of DNA called plasmids
Some have a flagellum which rotates
Can be seen under a electron microscope
