Unit 1 Flashcards
What is DNA?
- Deoxyribonucleic acid
- two polypeptides in a helix shape
- antiparallel backbone, 3’ hydroxide end and 5’ phosphate end
- directs synthesis of mRNA
- provides directions for self-replication
What is RNA?
- ribonucleic acid
- one polypeptide, shape is not helical, complementary bonding can happen with itself or with another RNA
- mRNA interacts w/ protein-synthesizing systems to make a polypeptide
What are the base pairing rules?
In DNA
- Adenine and thymine
- Cytosine and guanine
In RNA
- Adenine and uracil
- Cytosine and guanine
- bonded though hydrogen bonds
What are the four levels of protein structure?
- Primary
- Secondary
- Tertiary
- Quaternary
Primary protein structure
- sequence of amino acids that form the polypeptide chain
- determined by inherited genetic information
Secondary protein strucure
-coils and folds in the polypeptide chain
- resulted from hydrogen bonds in the peptide backbone
- forms an alpha helix or a beta pleated sheet
Tertiary protein structure
- formed by interactions between multiple side chains
- interactions between R groups, hydrogen bonds, ionic bonds. hydrophobic interactions
- brings together helix and sheet
Quaternary protein structure
- when there are multiple polypeptide chains
What is a proteins function determined by
Structure and function are directly connected
What is a protein’s structure determined by
the polypeptide chain aka the sequence of amino acids
What happens when a protein is moved to a different temperature or pH?
- the structure may change and it will start to unravel
- denaturation –> loss of protein’s native structure
- change in function
- may do something different, nothing, or will just not do its job as well
What are the 6 major elements of life?
Carbon, hydrogen, oxygen, nitrogen, sulfur, phosphorus
How do you identify a carbohydrate?
- carbon, hydrogen, oxygen
How do you identify a lipid?
- long carbon skeleton
- carbon, hydrogen, oxygen sometimes phosphate
- hydrophobic (fatty acid tail) and hydrophilic (phosphate/glycerol head) section
How do you identify a polypeptide?
- repeating structure
- carboxyl end and amino end (c-terminus and n-terminus)
- has R groups
- amino acid chain
- sulfur is mainly in this macromolecule
How do you identify a nucleic acid?
- made of nucleotides
- sugar and phosphate backbone with nucleotides in the middle
What macromolecule(s) is sulfur found in?
proteins
What macromolecule(s) is phosphorus found in?
Nucleic acids and phospholipids
What is the purpose of starch?
- storage polysaccharide (carb) for plants
- stores extra glucose monomers in chloroplasts and other plastids
- sometimes branched structure
What is the purpose of glycogen?
- storage polysaccharide (carb) for animals
- stores extra glucose in liver/muscle cells
- very branched structure
What is the purpose of cellulose?
- structural polysaccharide (carb) for plants
- strengthens the cell wall
- unbranched structure
Which fat is solid at room temperature, saturated or unsaturated?
Saturated fats
What’s the difference between saturated and unsaturated fats?
Saturated –> no double bonds, solid at room temperature, animal fats, have as many hydrogen atoms as possible
Unsaturated –> liquid at room temperature, oils, plant and fish fats, have at least one double bond
Hydrogenation adds hydrogen making an unsaturated fat saturated.
Why do hydrogen bonds form between water molecules?
- have polar covalent bonds
- oxygen has a slight negative charge and hydrogen has a slight positive
- oxygen is more electronegative so the electrons are closer to them
