Chapter 2 Cell Structure and Function

Lesson 1: Cells and Life (pages 42 – 48)

Basic Cell Substances• What is a macromolecule?

o Large organic molecules that form when smaller molecules are joined together.

o Many times made up of repeating subunits.

Basic Cell Substances

• Water:o Essential to all lifeo Makes up 70 percent of

a cell’s volume.o Surrounds and insulates

cells to help maintain homeostasis.

o Dissolves substances so they can move in and out of the cell.

Basic Cell Substances

• Watero The chemical

properties of water help it to dissolve substances.

Positive end

Negative end

Basic Cell Substances• Water

o The negative and positive ends help water dissolve substances such as salt.

https://www.youtube.com/watch?v=EBfGcTAJF4o

Basic Cell Substances

• Why is it important for cells to have substances dissolved in water?o Large Molecules – such as glucose - need to be

dissolved (in liquid form) in order to pass in and out of the cell.

Glucose

Water Oxygen Carbon Dioxide

Basic Cell Substances

• Four Basic Macromolecules that make up living cells.oCarbohydrateo Proteino LipidsoNucleic Acids

MacromoleculesMacromolecule Description Examples Major role in living things

Nucleic Acid

Protein

Lipid

Carbohydrate

Macromolecules made up of long chains of nucleotides.

Macromolecules made up of long chains of amino acids.

A large macromolecule that does not dissolve in water.

A macromolecule made up of one simple sugar, or a long chain of sugars molecules

DNA or RNA

amylase, keratin

cholesterol, phospholipids, vitamin A

sugar (fruit) and starches (bread)

-Contain genetic information that is passed from parent to offspring.

-help cells communicate-transport substances-break down nutrients-provide structural support

-help form protective barriers-major part of cell membrane-energy storage-help cells communicate

-structural support-energy storage-help cells communicate

Carbohydrates• Sugars and starches are both examples of

carbohydrates.• What is the relationship between a sugar

and a starch?

Glucose (sugar) Starch

Nucleic Acids• Nucleic Acids - such as DNA and RNA

- are made up of repeating units called Nucleotides.

Proteins• Proteins are made up of repeating

units called amino acids.

Lipids• Large macromolecules that are not

soluble in water.• This inability to dissolve in water allows

lipids to form protective barriers in cells.

Lipids are the major component in cell membranes