All matter in the universe consists All matter in the universe consists of elementsof elements
An element is a pure substanceAn element is a pure substance
Examples of elements needed for life:Examples of elements needed for life:CarbonCarbon CCHydrogenHydrogen HHOxygenOxygen OONitrogenNitrogen NNPhosphorusPhosphorus PPSulfurSulfur SS
An atom is the smallest part of an An atom is the smallest part of an elementelement
Can only be seen with the most powerful microscopeCan only be seen with the most powerful microscope
Atoms join together to form molecules.Atoms join together to form molecules.
Examples: Examples: Oxygen we breathe is a molecule made up of 2 oxygen Oxygen we breathe is a molecule made up of 2 oxygen
atoms: Oatoms: O22
Water is 2 hydrogens with 1 oxygen: HWater is 2 hydrogens with 1 oxygen: H22OO
Sugar is a much bigger molecule: CSugar is a much bigger molecule: C66HH1212OO66
How many atoms in one sugar molecule?How many atoms in one sugar molecule?
How do atoms join?How do atoms join?
1.1. Ionic bonds: atoms with opposite Ionic bonds: atoms with opposite charges are attracted to each othercharges are attracted to each other
Example: table salt: NaClExample: table salt: NaCl
2.2. Covalent bonds: strong bonds!Covalent bonds: strong bonds!
Takes energy to break them apartTakes energy to break them apart
Example: water, sugarExample: water, sugar
Important molecules for lifeImportant molecules for life
***Water******Water***
We take it for granted, but water has many We take it for granted, but water has many unique properties that support life.unique properties that support life.
In fact, scientists who look for life on other In fact, scientists who look for life on other plants focus on places where water does plants focus on places where water does or used to existor used to exist
Properties of water
Polar molecule, hydrogen bonds Universal solvent High specific heat Cohesion, adhesion Less dense as a solid (so ice floats) Neutral pH (not an acid or base) Exists on Earth mostly as liquid
2. It can make many different kinds of molecules
Carbon can bond with one, two, three or four other atoms—and it can bond with other carbon atoms to form rings or long chains
The bonds it forms are strong covalent bonds.
Four types of organic compounds found in living things
Carbohydrates Lipids Proteins Nucleic Acids
These are called macromoleculesMacro = giant (opposite of micro)http://www.authorstream.com/Presentation/PKYonge-422910-pky-biology-macromolecules-macdonald-narrated-education-ppt-powerpoint/
Carbohydrates
Provide the quick energy that powers all cell functions
Some energy storage (short term) Structural building block
--cellulose—plant cell wall
--chitin—animal exoskeleton
Sugars
All carbs look like this in their simplest form. This is called a simple sugar or monosaccharide.
mono = one saccharide = sugar
Monosaccharides are building blocks for other sugars. If you put two of them together you get this. It’s called a disaccharide. Di = two
If you string a bunch of monosaccharides together you get a polysaccharide. They look like this. Poly = many
Starches
Polysaccharides are starches.
Plant starch
Amylose – surplus glucose storage Cellulose – structural support in the form
of cell walls
Animal starch
Glycogen – one-day store of glucose in liver and muscles
Chitin – exoskeleton of some insects and cell wall of some fungi
Review
What are carbohydrates made of? What is their major role in the cell? What two major groups are carbohydrates
divided into? What are the building blocks of
carbohydrates? How is starch different from sugar? How are carbohydrates named?
Lipids
Main purposes:1. Storage of energy. In case
you run low on carbs
2. Thermal insulation.
3. Cushioning for delicate organs such as the heart.
4. Waterproofing. Like the wax in your ears.
Lipids
All lipids are formed from carbon, hydrogen, and oxygen.
Unlike other macromolecules, they are not polymers (made from many copies of one unit or mer)
All lipids are hydrophobic (literally afraid of water): they will not dissolve in water because they are nonpolar molecules.
Fats and oils
Glycerol (an alcohol) + 3 fatty acids
Fats are solids at room temperature while oils are liquids
Steroids
Cholesterol
Precursor molecule For Vitamin D For hormones such as
Testosterone and Estrogen
Review
What are the different groups of lipids? How are lipids similar to carbohydrates? What property do all lipids share? What important purposes do lipids serve?
ProteinsProteins are composed of 4 elements: carbon, hydrogen, oxygen and nitrogen. The basic unit is called an amino acid and it looks like this.
This is a 3-D image of a protein containing thousands of amino acids connected together & folded to make this distinct shape.
Proteins
All proteins are made from 20 amino acids. Each amino acid is different in one side chain: the “R” in the graphic
A chain of amino acids is called a polypeptide because it is formed by joining amino acids with peptide bonds.
Proteins
Their role in the body: Important part of structures like skin and muscle Antibodies – fight disease Transport – like hemoglobin, the part of blood
that carries oxygen to each cell Regulate what enters and leaves cells –
channels in cell membranes Enzymes – catalyze reactions (lower the amount
of energy needed for chemical reactions essential to cell function to take place)
http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_enzymes_work.html
Proteins make you who you are.
The job of each gene of your DNA is to make a protein with a specific job within the cell.
Nucleic Acids
DNA and RNA!
Their job is to store all your
hereditary information.
More on them later!