What are the different types on polysaccharides and what are their purpose? (4)
- Starch (plant) and glycogen (animal) - energy storage:
They are not as soluble in water, so they cannot easily move in or out of cells - Cellulose (cell walls of plants) and chitin (exoskeleton) - structural
proteins
- are polymers composed of amino acid monomers.
- Amino acids: Central carbon atom bonded to three functional groups.
> Amino group (—NH2).
> Acidic group (—COOH).
> R group varies; determines uniqueness of amino acid.
A protein is _______ when it loses structure and function.
denatured
> Occurs when proteins are exposed to extreme heat or pH.
triglyceride
- A fat molecule
- Consists of:
> one glycerol backbone.
> three fatty acids.
lipids
- Lipids are diverse in structure and function.
- Lipids have one common characteristic: They do not dissolve in water (hydrophobic), due to their hydrocarbon chains.
- Lipids contain more energy per gram than other biological molecules.
- Types:
> Fats and oils are used for energy storage.
> Phospholipids form membranes.
> Steroids include sex hormones.
Levels of Protein Organization (4 levels)
- Primary structure: linear sequence of amino acids
- Secondary structure: when polypeptide takes on a certain orientation in space
- Tertiary structure: final 3-dimensional shape
- Quaternary structure: when 2 or more polypeptides interact
Functions of proteins (7)
- Structural proteins give support (keratin, collagen).
- Enzymes speed up chemical reactions.
- Hormones are chemical messengers.
- Actin and myosin move cells and muscles.
- Some proteins transport molecules in blood.
- Antibodies protect cells.
- Channels allow substances to cross membranes.
monosaccharides
- are sugars with three-to-seven carbon atoms
- Pentose refers to a five-carbon sugar.
- Hexose refers to a six-carbon sugar, such as glucose.
polysaccharides
- are long polymers that contain many subunits.
What are the differences between saturated, unsaturated, and trans-fats?
- Saturated fatty acids have no double bonds between carbon atoms.
>Saturated with hydrogen atoms. >Solid fats
>Flat molecules that easily stick together in the blood - Unsaturated fatty acids have one or more double bonds between carbon atoms.
>Liquid fats. >Healthier for you, but have a shorter shelf life - Trans-fats are oils hydrogenated to make them solid; processed food.
>Chemically produced by adding hydrogen to vegetable oils. >Added to processed food for a longer shelf-life
Polymer
Large organic molecules formed by combining monomers.
peptide
- A polypeptide is a single chain of amino acids.
* A peptide bond joins two amino acids.
phospholipids
- are comprised of two fatty acids and a phosphate group.
- The phosphate group is polar and forms the hydrophilic head of the molecule.
- The fatty acids are nonpolar and form the two hydrophobic tails of the molecule.
- Spontaneously form a bilayer in which the hydrophilic heads face outward toward watery solutions, and the tails form the hydrophobic interior.
- Phospholipids make up animal cell walls.
Monomer
Repeated subunit of many large organic molecules.
hydrolysis
components of water are added when polymers are broken down
Distinguish a monomer from a polymer
- Polymer means many monomers. Sometimes polymers are also known as macromolecules or large-sized molecules. Usually, polymers are organic (but not necessarily).
- A monomer is a molecule that is able to bond in long chains.
dehydration
an −OH and −H are removed as a water molecule when monomers are joined to build polymers.
