Chapter 9

Energy in a Cell

What would you do if you need to buy a soda but had a 100 dollar bill?

•All living things need energy to survive.

•They get energy from the things around them.

•Several cell process require energy.

•Cell division, movement, storage of protein are a few examples.

•How about your muscles working, heart pumping and brain activity.

Adenosine TriphosphateATP

• This is made up of one adenosime molecule and 3 phospate molecules.

• Phosphate molecules are charged – molecules of the same charge don’t like being around each other.

• AMP(adensoine monophosphate)•Not much energy

• ADP(adensoine triphosphate)• More energy neededWhen the bonds are broken, energy is

released!

When the bond is broken between the 2 and third phosphate group is broken – energy is release and ATP becomes ADP

Like the 100 dollar bill

• When broken down, the cell can use the energy.

• Proteins have a site where ATP can bind. This makes the energy usable for the cell

aka – enzymes!!!!Remember, enzymes help chemical

process in the body!

Cells use energy:

•Maintaining homeostatsis•Move molecules and ions•Making new molecules

Photosynthesis

2 phases to photosynthesis

• Light-dependent reaction –•Covert light energy into chem.

energy• Light-independent reaction –

•The ATP molecule produced in the light are used to fuel and produce simple sugars.

Chloroplast and pigment

• Light reactions take place in the thylakoid discs in the CP

• Cholorophyll absorbs most wave lengths green – that is why plants are green! The color is the reflection

Light Dependant

• 1 st phase of photo. Syth.• Chlorophyll molecules transfer the

energy in the light to electrons. The energy is then passed on through an electron transport chain

• Protiens “pass” the energized electrons along. Sometimes the energy spills out and forms ATP from ADP

After the e- have traveled down the chain they are reenergized are passed down a second chain. At the bottom of this chain NADP+ is used. This combines with 2 e- and a H ion to become NADPH. The energy is stored here

NADPH – important to light independent reaction pg227

Light-Independent Reaction

• 2 nd phase of photo synth• CALVIN CYCLE - uses carbon

dioxide to form sugars• Takes place in the chloroplast

• Read aloud Light-Independent Reactions

• Page 229