Biology—chemical reactions

Element-matter that can not be broken down into a simpler substance

There are 92 known elements and all are shown of the periodic table

Each element has a symbol ex. H-hydrogenElements differ from one another by the number of protons they have

(atomic number) (example: hydrogen has 1 proton/carbon has 6 protons)

Metals are on the left of the dark line/nonmetals are on the right

Chemical formula- tells the number of elements present and how many of each element example water has 2 hydrogen and 1 oxygen

Why is water so important to life?

1. Absorbs heat to keep the temperature stable

2. Good lubricant (ex. Tears in eyes)

3. Needed for reactions

4. Dissolves a lot of substances (universal

solvent) ex. Water in bloodtransports nutrients

Organic molecules- contain carbon(except Carbon dioxide)

types of organic macromolecules in humans

1. Carbohydrates

2. Lipids-fats

3. Proteins

4. Nucleic acids

Carbohydrates

• Composed of C, H, O

• Monosaccharides are the simplest units that make them up2 monosaccharides form disaccharidemany monosachharides form

polysachharides

Lipids- fats

• Composed of C, H, O, N, P• Glycerol-smallest units that

make up lipids-used to repair tissue

2 types of fats:

• Saturated fat- all carbons have a single bond

• Unsaturated fat- all carbons do not have a single bond(easier to break down)

Proteins

• Made of C, H, O, N, S• Amino acids are the smallest

unit that makes them up.

There are 20 amino acids

putting these in different

combinations results in

different proteins

Enzyme- protein that speeds

up reactions

Nucleic acids

• Made of C, H, N, O, P• Nucleotides-smallest

unit that makes up nucleic acids

There are 2 kinds of Nucleic acids:

DNA (deoxyribonucleic acid)

RNA (ribonucleic acid)

DNA and RNADNA- genetic material of the cell RNA- protein synthesis

-controls the cells activities (makes proteins)

-found in the nucleus -found in ribosomes

DNA structure– consists of a double RNA structure- consists of

helix (2 strands of nucleotide 1 strand of nucleotides

coiled together)

2 main chemical reactions that occur in living things

• Photosynthesis-uses light energy to convert inorganic material to sugar.

• Respiration-breaks down glucose to give off energy

(energy)

                                                                                     

Photosynthesis• Process used by a plant to make its own

food

• Ingredients needed are: Carbon Dioxide (CO2), water (H2O) and energy from sun

• Products are: Oxygen (O2) and glucose (C6H12O6)

• The process of photosynthesis occurs in the leaves

• In leaves, the carbon dioxide, water and energy combine to form glucose and oxygen

Equation for photosynthesis• CO2+H2O+sun’s energy C6H12O6 + 02

(glucose)

We get our oxygen supply from plants because they produce it in photosynthesis!

Photosynthesis occurs in 2 phases:• 1. Light dependent reaction-

uses the sun and the chloroplast to convert light energy to chemical energy (ATP)

• 2. light independent reaction (Calvin Cycle)– does not need sunlight for this

phase– takes the ATP energy and

makes the glucose

Respiration

• In order for organisms (like animals) to have energy for their cells to function, they must:– 1. ingest glucose from plants – 2. convert it to a form of energy that their cells

can use (ATP).

• The energy form that animal cells use is called ATP (Adenosine Triphosphate)

Respiration cont…

• The process of converting glucose to ATP is called respiration (burning of glucose)

• It occurs in the mitochondria of cells

Equation of respiration:

O2+C6H12O6 (glucose)CO2+H2O+ATP (energy)