Chapter 3 Notes

Talon
Chapter 3
The Chemistry of Life (from your text book)

See table on Page 69.

Elements that make up the Human Body -Highest percentage on top
Oxygen
65.0
Carbon
18.5
Hydrogen
9.5
Nitrogen
3.2
Calcium
1.5
Phosphorus
1.0
Potassium
0.4
Sulfur
0.3
Sodium
0.2
Chlorine
0.2
Magnesum
0.1

The study of chemistry plays a huge role in the study of biology.

Organic compounds: Contain carbon and hydrogen

Lipids- fats, oils, waxes, phospholipids, cholesterol- do not mix with water. (hydrophobic)

Carbohydrates- sugars, starch, cellulose, supply energy or serve to give structure to plant cells (cellulose)

Protiens- Enzymes, hormones, skin, hair, tissues, DNA codes for protein, made up of amino acids, muscle contains large amounts of protein. Enzymes regulate all chemical reactions in cells.

Nucleic Acids- DNA, the genetic material, RNA, used to make enzymes and other proteins.

Inorganic compounds- non-carbon compounds.

Water- VERY important, used in every process in the body (adult 60% water) 2/3rds are inside cells

Other important compounds-
Calcium phosphate- gives strength to bones
Hydrochloric acid- breaks down food in the stomach
Sodium bicarbonate- helps the digestion of food to occur
Salts, KCl, NaCl- important in sending messages along nerves.

What's the difference between a substance and a mixture?
A mixture can be seperated by ordinary processes. A mixture is made up from a combination of different substances.
Substances have only one property.

Ex. Mixture- iron filings and sand
Substance- Salt

Chapter 3 section 2-
Passive transport- movement of substances through the cell membrane without the use of energy
Active transport- Movement of substances through the cell membrane with energy

Diffusion- When molecules more from an area of higher concentration to an area of lower concentration (ex) when someone sprays axe in a corner of a room it will diffuse till all the molecules are spread evenly throughout the room

When molecules are spread evenly we call that "Equilibrium"

Osmosis- Diffusion through a membrane like a cell membrane. In a cell water or other materials may diffuse in or out through the membrane.

Cell membranes are called "Semi-permeable" because they let some things in but not all. You could think of this like a screen on a window; it lets air in but not bugs.

Endocytosis- When a cell takes in large particles by surrounding it with a membrane.

Exocytosis- When a cell gets rid of a large particle in the opposite way of endocytosis



Chapter 3 section 3
Energy for Life
How do we get energy? Ultimately- the sun
Directly- we eat food

Food must be changed into useable forms.

Metabolism- The total of all chemical reactions in an organism

Catalyst- substance that speeds up or causes a reaction to happen

Enzymes- Help reactions take place in the body. The “catalysts of the body”

Photosynthesis- Plants use water, sunlight, and carbon dioxide to produce their energy which is sugar. Oxygen is a byproduct of the reaction, this benefits us. This is very important in the reduction of greenhouse gases.

Light energy+ carbon dioxide+ water -> Sugar (glucose) + oxygen

Respiration- Chemical reactions that break down food into simpler substances we can use (enzymes involved) Takes place in the mitochondria

Breaking down Carbohydrates- respiration happens in the cytoplasm. Carbohydrates are broken down into glucose. Glucose is broken down into two simpler molecules….. See below.
Digestion Glycolisis fermentation Krebs cycle
Carbohydrate--> glucose->2 molecules of pyruvate-> 2 acetyl groups->2 molecules of ATP

The whole process uses energy and creates waste products of CO2 and water.

Fermentation- (in the cytoplasm)- release of energy anaerobically (without oxygen)
Examples: Running- burning buildup of lactic acid.
Bread dough rising- yeast ferments sugar in dough and excretes a gas
Alcohol- product of fermentation
Bacteria- breakdown sugar in milk to make yogurts and cheeses