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

nutrients2. Convert nutrient macromolecules into building

blocks of cell macromolecules3. 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 occur2. 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 MaltoseAmylase

ANABOLIC REACTIONS

• Energy is NEEDED

Example: protein building within the ribosome

Example: glucose-1-phosphate starchphosphoylase

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