Metabolic Pathways + Membranes

Question 1

what is metabolism

Answer 1

all of the enzyme controlled reactions which take place in all cells

Question 2

what are metabolic pathways

Answer 2

integrated and controlled pathways of enzyme catalysed reactions within a cell

Question 3

what is catabolism? give one example

Answer 3

catabolism is the breakdown of complex molecules to simple molecules - this releases energy e.g. glucose to CO2 + H2O (ATP is produced)

Question 4

what is anabolism? give one example

Answer 4

anabolism is the SYNTHESIS (build-up) of simple molecules to complex molecules - this requires energy e.g. synthesis of amino acids to proteins (requires ATP)

Question 5

explain the importance of reversible steps in metabolic pathways

Answer 5

the ensure the concentrations of substances remain relatively stable within the cell

Question 6

explain the importance of irreversible steps in metabolic pathways

Answer 6

to commit the metabolic pathway to continuing

Question 7

explain the importance of alternative steps in metabolic pathways

Answer 7

if certain enzymes/substrates are plentiful/in short supply, steps in the metabolic pathway can be bypassed by an alternative route. the end product is still produced

Question 8

explain the importance of enzymes

Answer 8

enzymes are biological catalysts which speed up chemical reactions in the body without which, reactions would occur too slowly to maintain life

Question 9

describe the structure of membranes

Answer 9

membranes consist of proteins and phospholipids. proteins can form pores, pumps, and enzymes