MET

ABOLISM

SECTION

2-7

PAG

ES 62-6

4

C+C #

1,3,4

P.6

6

CHEMICAL REACTIONS IN ORGANISMS

METABOLISM: ALL CHEMICAL ACTIVITIES AND CHANGES THAT TAKES PLACE IN CELLS

(ANABOLISM + CATABOLISM = METABOLISM)

- BOTH ANABOLISM AND CATABOLISM INVOLVE FREE ENERGY

- ENERGY INPUT=ENERGY OUTPUT - IF ENERGY INPUT EXCEEDS ENERGY OUTPUT, GROWTH OCCURS

- IF ENERGY OUTPUT EXCEEDS ENERGY INPUT, WEIGHT LOSS OCCUR)

2 TYPES OF METABOLISM

1. BIOSYNTHESIS (ANABOLISM) BUILD UP, FORM NEW PRODUCTS, USING

“BUILDING BLOCKS” SMALL LESS COMPLEX TO LARGE COMPLEX

MOLECULES (MONOMERS TO POLYMERS) EXAMPLES: PHOTOSYNTHESIS AND

CHEMOSYNTHESIS

2. DECOMPOSITION (CATABOLISM) THE BREAKDOWN OF SUBSTANCESLARGE COMPLEX MOLECULES ARE BROKEN DOWN INTO SMALL SIMPLER ONES

EXAMPLE: CELLULAR RESPIRATION

SECTI

ON 2-8

P.64-6

6

ENER

GY TRANSFE

R

AND ATP

THE STRUCTURE OF ATP

ATPADENOSINE TRIPHOSPHATE

- ADENINE (THE NITROGEN BASE)

- RIBOSE (THE 5 C SUGAR)

- 3 PHOSPHATES (PHOSPHORIC ACID)

THE EQUATION FOR ATP BREAKDOWN

 ATP ADP + P + ENERGY - ADP: ADENOSINE DIPHOSPHATE- A-P-P~P (WRITTEN OUT)- ~ = HIGH ENERGY BOND BETWEEN

PHOSPHATES 2 AND 3

*WHEN THIS BOND IS BROKEN, ENERGY IS RELEASED FOR THE CELL TO USE*

*CHEMICAL ENERGY IS TRANSFORMED INTO FREE ENERGY*

THE ATP CYCLE

KNOWN AS A COUPLED REACTION SINCE IT IS CYCLICAL