BIOLOGY

Unit 1 Notes:Characteristics

of Life & Biomolecules

(1) Characteristics of Life• All systems classified as “living” must be able to do

the following on their own:– Reproduce + Pass on genes– Evolve + Respond + Adapt to their changing

environment– Metabolize nutrients + Excrete Waste– Grow + Develop over time– Maintain Homeostasis

(2) Homeostasis• Maintaining internal stability / balance.

• What Does This Mean?– When something changes inside/around an organism, it

must be able to get itself back to a “healthy normal”.– Examples:• Shivering when cold• Making more red blood cells when oxygen levels drop• Releasing bicarbonate when you eat something acidic

(3) The Cell Theory• Once we know something is living, we also know it

must follow the Cell Theory:– All living things are made of cells.– Cells are the most basic unit of life.– Existing cells come from pre-existing cells.

(4) The Biological Elements• The element that make up all living organisms:– C (carbon)– H (hydrogen)– O (oxygen)– N (nitrogen)– P (phosphorus)– S (sulfur)

(5) The Magical Carbon Atom• Carbon is one of the most important elements

found in living systems.

• What Makes Carbon So Special??– Able to form 4 different bonds.– Can position and rearrange itself into a lot of different

types of formations and molecules.– Allows for the wide variety of structures in living things.

(6) Wonderful Water• ~70% of a cell is made up of water!

• Water Allows For:– Special chemical reactions needed to release and store

energy.– The dissolving of solutes (like sugars and salts).

• What Makes Water So Special??– Polar Molecule– Allows for unique interactions with polar and non-polar

molecules in cells.

(7) The Biomolecules• The molecules that make up all living organisms:– Carbohydrates– Lipids– Proteins– Nucleic Acids

(8) Carbohydrates• Function: Provide immediate and intermediate

energy.

• Monomers: Monosaccharides (Glucose, Fructose)• Polymers: Polysaccharides (Starch, Wheat)

• Draw A Picture:

Monosaccharide

Polysaccharide

Energy Stored In Bonds Energy Available to Cells When Bonds Broken!

Why Do You Think People Say Wheat / Multi-Grain Carbs Are Better For You Than Simple Sugars?!?

What Are The Pros + Cons Of Each??

(9) Lipids• Functions: – Long term energy storage.– Make up cell membranes.

• Monomers: Fatty Acids + Glycerol• Polymers: Fats, Oils, Phospholipids

• Draw A Picture:

Glycerol

Fatty Acids

Hydrophilic Head:-Water Loving-Polar

Hydrophobic Tails:-Water Fearing- Non Polar

Phospholipid

(10) Proteins• Functions:– Provide the expression of the instructions within DNA.– Catalyze chemical reactions.

• Monomers: Amino Acids• Polymers: Proteins / Polypeptides

• Draw A Picture:

Amino Acid

Polypeptide

Peptide Bonds

The Amino Acids Bond Together In A Very Specific Order + Structure!

(11) Nucleic Acids• Function: Provide the genetic instructions for all

cell parts and processes.

• Monomers: Nucleotides• Polymers: DNA and RNA

• Draw a Picture:

Nucleotide

Phosphate

Sugar

NitrogenousBase

DNA RNA