B4 Respiration and Metabolism (page 54) Flashcards
You need energy to keep your body going. where does Energy come from?
it comes from food and it’s transferred by respiration.
Respiration involves many reactions, why are they important?
they are really important reactions as respiration transfers the energy that the cell needs to do just about everything - this energy is used for all living processes.
Is Respiration breathing in and breahing out?
No, many people believe this, but this is not correct.
What is Respiration?
it is the process of transferring energy from the breakdown of glucose (sugar) - and it goes on in every cell in your body continuously.
Do Respiration happen in plants too?
Yes
All living things respire. Its how they transfer energy from their food to their cells.
What is the process of Respiration?
it is the process of
TRANSFERRING ENERGY FROM GLUCOSE, which goes on IN EVERY CELL.
Respiration is Exothermic, what do this mean?
it transfers energy to the enviornment
(exothermic means of a reaction or process accompanied by the release of heat).
Respiration transfers energy for what?
all kinds of things.
Give some examples how organisms use the energy transferred by respiration?
1) To build up larger molecules from smaller ones (like proteins from amion acids).
2) In animals it’s used to allow the muscles to contract (so they can move about)
3) In mammals and birds the energy is used to keep their body temperature steady in colder surroundings (unlike other animals, mammals and birds keep their bodies constently warm)
What is Matabolism?
it is all the Chemical Reactions in an Organism.
In a cell there are lots of chemical reactions happening all the time, what are they controlled by?
enzymes
(enzymes are biological catalysts see page 25).
Many of these reactions are linked together to form bigger reactions
enzyme enzyme enzyme reactant >>>>product >>>> product >>>>product
In some of these reactions, larger molecules are made from smaller ones, give example?
1) Lots of small glucose molecules are joined together in reactions to form starch (a storage molecule in plant cells and cellulose (a component of plant cell walls.
2) Lipid molecules are each made from one molecule of glycerol and three fatty acids
3) Glucose is combined with nitrate ions to make amino acids, which are then made into proteins.
In other reactions, larger molecules are broken down into smaller ones, give example?
1) Glucose is broken down into respiration. Respiration transfers energy to power all the reactions in the body that are molecules
2) Excess Procein is broken down in a reaction to produce urea. Urea is then excreted in urine.
(urea is a substance formed by the breakdown of protein in the liver).
The sum (total) of all of the reactions that happen in a cell or the body is called what?
Metabolism.
Give two examples of how animals use the energy transferred by respiration (2 marks)
Any two from:
e.g. to build up larger molecules from smaller ones
To contract muscles
To keep body temperature steady (1 mark for each)
