METABOLISM AND ENZYMES

WHERE HAVE YOU HEARD THE TERM METABOLISM BEFORE?

METABOLISM The SUM of all reactions that occur within cells All the enzyme-controlled reactions within the human body and the pathways they form Functions: 1.Obtain energy from the breakdown of nutrients 2.Convert nutrient macromolecules into building blocks of cell macromolecules 3.Assemble these building blocks into proteins, nucleic acids, lipids, polysaccharides

CATALYST Chemicals that make reactions happen faster! Functions: 1.Lower the energy input needed for reactions to occur 2.Speed up chemical reactions

CHALLENGE By changing just one letter at a time, get from ‘Tread’ to ‘Blink’. All steps must be real English words. TREAD _____ BLINK

CHALLENGE TREAD initial substrate BREAD BREED BLEED Intermediates BLEND BLIND BLINK end product

METABOLIC PATHWAY Reactions in the body that are linked together Process in which food is broken down with the ultimate goal of producing energy in the form of ATP (adenosine triphosphate) The PRESENCE OR ABSENCE of a particular enzyme controls pathway activity Substrate  A  B  C  D  Product

CATABOLIC REACTIONS Energy is RELEASED Example: cellular respiration Example: Starch  Maltose Amylase

ANABOLIC REACTIONS Energy is NEEDED Example: protein building within the ribosome Example: glucose-1-phosphate  starch phosphoylase

ACTIVATION ENERGY The energy required to initiate a chemical reaction What do enzymes do? They lower the amount of energy required for a reaction to occur Does this by stressing the bonds in the substrate so that less energy is needed