CHEMICAL REACTIONS TAKE PLACE INSIDE CELLS

Chapter 2-1

4 TYPES OF LARGE MOLECULES

These molecules have specific jobs in the cell.

Carbohydrates Lipids Proteins Nucleic Acids

CARBOHYDRATES

Provide the cell with energy and support They are sugars (starch, cellulose, and glycogen) Energy

Plant cells make sugar during photosynthesis Sugar is stored at starch

Support Plant cells also make cellulose

for support

Where do all carbohydrates come from? Plants

LIPIDS

Make up the cell membrane Fats, oils, waxes:

What happens when they mix with water? Does not mix.

The double layer keeps water in or out of the cell.

PROTEINS (AMINO ACIDS)

How to you get proteins? From the food you eat.

Made of amino acids Jobs:

Proteins control the chemical activity of a cell and support growth and repair.

NUCLEIC ACIDS

Two types DNA and RNA Holds the instructions for maintenance ,

growth and reproduction in the cell DNA holds the information RNA takes the information where it is

needed.

2/3 OF EVERY CELL IS WATER

All chemical reactions take place in water

In the cell membrane the tails repel water and the heads attract water. Keeps water from going in or out of a

cell See page 45