Lecture 2 Flashcards
What are polymers?
A chain of repeating monomers that are similar but not identical
What are proteins? How do you classify them?
Polymers of amino acids that are classified by their R group
What is a protein made up of?
The base of a protein is made up of NH3+, C, H and COO-. An R group is attached to this base. The C is a carboxy group and the N is a amino group
How do you classify and R group?
An R group can be non-polar, polar uncharged, polar charged acidic and polar charged basic
How do you know what to classify an R group?
Non-polar=CH Polar uncharged= -OH or -SH Polar charged acidic=there is negative charge Polar charged basic=there is a positive charge
What is the directionality of proteins? Extensibility?
N to C or NH3+ to COO-. Other proteins can be added but N always has to be start and C always has to be end
What is 1°?
Primary Structure. It dictates folding and folding dictates functions
What is 2°?
Secondary Structure. The a.a fold into a Beta Sheet and/or an Alpha Helix
What is 3°?
Tertiary Structure. 3D folding, hydrophobic R groups drive a.a away from water into middle of protein
How is 3° maintained?
Covalent bonds- disulfide bridges between 2 cytosine. Ionic Bonds- between oppositely charged a.a. Hydrophobic interactions- between nonpolar a.a. Hydrogen bonds- between polar uncharged a.a
What is 4°?
Some proteins form multisubunit complexes that create a functional protein. Held together by same forces as 3
What is a Nucleosome?
DNA coiled around histones, this is an example of 4° structure
What is DNA? What is its directionality?
A polymer of Nucleotides. Its directionality is 5 to 3
What are the 4 nucleotides?
A, G, T, C
How do you identify a Nucleotide?
A=purine/double ringed, has no O’s in the base. G=purine/double ringed, has O’s in the base. T=pyrimidine/single ring, 3 functional groups. C=pyrimidine/single ring, does not have 3 functional groups
What is a Sugar? What is its function?
Sugars are polymers of mono or disaccharides. They are an energy source, the are essential to cell structure and they assist in cell-cell recognition.
What is starch? What is its structure?
Starch is a polysaccharide that is energy storage for plants. It is a polymer of glucose. It contains an alpha 1-4 carbon glyosidic bond. Animals can beak done the alpha bond
What is cellulose? What is its structure?
Cellulose is a polymer of glucose and is the cell wall in plants. It contains beta 1-4 carbon glyosidic bonds. Only bacteria can break down beta bonds
What is peptidoglycan?
Polymer of NAG and NAM. It is the structural basis for bacteria cell walls. It has directionality of C1-C4
What is a glyosidic bond?
A covalent bond between sugars
What are the 2 ways to create and destroy polymers?
Synthesis-condensation/dehydration reactions. Breakdown-hydrolysis reaction
How does hydrolysis work?
Water is added to a a polymer and splits monomers apart. Energy is released. The reaction is spontaneous but slow.
How does Synthesis work?
Add monomers to a growing reaction chain, a covalent bond forms between them. This requires energy and water is a product.
What are lipids?
Not a true polymer, they are made mostly of HC. Are hydrophobic and aggregate away from water
What is a fatty acid?
Single chains of mostly HC with a COOH end. Then can esterify to a glycerol
What is Fat?
Three fatty acid tails esterify with a glycerol and create triglyceride which is animal fat. Function as energy storage and insulation
What is the difference between saturated and unsaturated fats?
Saturated fats are linked with all single C bonds, meaning the fatty acids tails are straight. Unsaturated fats are linked with double C bonds, meaning the fatty acids have a kink
What are phospholipids?
Phospholipids have a hydrophilic head made of phosphate which is connected to fatty acid tails with glycerol. The fatty acid tails are hydrophobic. The entire phosphide is amphpalic meaning it has a hydrophilic domain and a hydrophobic domain.
How do phospholipids form? Do they have covalent bonds?
Phospholipids have no covalent bonds and spontaneously self assemble
What is a steroid? What is its structure? What do the do?
A steroid is a class of lipids based on cholesterol. They have a backbone of 4 HC groups and also a small polar functional group. They are hormones.
How are amino acids bonded?
A peptide bond between a carboxy and amino group
What is the structure of DNA?
A 5 carbon sugar (called a ribose), a nitrogenous base and a phosphate
What attaches to each Carbon in DNA?
C1- attaches to base. C2- attaches to nothing/H(but in RNA it attaches to OH. C3- attach to 3’ OH which is essential for polymerization. C4- boring. C5- attaches to phosphate
