2. Molecules of Life Flashcards
What is the difference between orbitals + shells
- orbital: the region around the nucleus that the electron moves in (each orbital has 2 electrons)
- shell: the energy levels. depending on the energy level, there can be multiple orbitals
What is the universal solvent
Water
What are the 4 types of biological molecules, and which ones are polymers?
Polymers
- Proteins
- Nucleic acids
- Carbohydrates
Not a polymer
- Lipids
What happens to energy + water in a condensation reaction
Monomers combine with each other to form covalent bonds:
- Requires energy, releases water
What happens to energy + water in a hydrolysis reaction?
Polymers break down into monomers:
- Releases energy, requires water
lysis - splitting
“splitting of the water molecule”
What is the monomer of proteins? What types of bonds connect the monomers?
- Amino acids
- Connected via peptide bonds
peptide bonds are formed via:
- one Oxygen from the carboxyl group
- 2 Hydrogens from the nitrogen (amino group)
Name the 4 connections to the alpha carbon of an amino acid
- Hydrogen (H)
- Amino group (NH2)
- Carboxyl group (COOH)
- R group
What is the monomer of nucleic acids? What types of bond connect the monomers?
- nucelotides
- phosphodiester bonds
What are the two types of nucleic acids, and what is the chemical difference between them?
Deoxyribonucleic acid (DNA)
- Has deoxyribose as their 5-carbon sugar
- Uses the bases: A, T, C, G
Ribonucleic acid (RNA)
- Has ribose as its 5-carbon sugar
- Uses the bases: A, U, C, G
think, T first then U (DNA first then RNA)
What are the parts of a nucleotide?
- A nitrogen containing base
- A 5-carbon sugar
- One or more phosphate groups
visually…
5 carbon sugar forms a ring
- One side carbon attaches to phosphate group: PO4
- Other side carbon attaches to base
What is the difference between Pyrimidine and Purine?
Both are nitrogen containing bases that make up one of the parts of a nucleotide
- Pyrimidine: Contains a single ring (C, T, U)
- Purine: Contains a double ring, like an 8 (A, G)
What is the difference between a nucleoside and a nucleotide? What differs in their use?
Nucleoside: Has no phosphate group
- Just the base + sugar
Nucleotide: Has 3 parts
- base, sugar, phosphate group
Nucleotides are monomers for nucleic acids, nucleosides precede the nucleotide
Why do we care about the phosphate group?
- The existence of a phosphate group determines whether or not we can create ATP
- We can create ATP with nucleotides, but not with nucleosides
What else do nucleotides do aside from being monomers of DNA and RNA?
- signal molecules
- transfer of energy in metabolism: cleaves off the phosphate group to release stored energy
Which side fo the chain is the beginning of the nucleic acid, and which side of the chain do you add nucleotides to?
5’ is the beginning (phosphate)
add new nucleotides to the 3’ end
- to the OH which is on the 3 carbon sugar
- Results in OH being used in condensation reaction to form water
Why is it beneficial for hydrogen bonds to form between nucleotide bases?
Allows DNA to “unzip” down the middle, while still being stable as a whole
- Pairings are due to the number of H bonds between bases
- Etc. 3 H-bonds between C-G
- Etc. 2 H-bonds between A-T
What are the complementary base pairings of DNA?
A-T
C-G
What is the ratio of C:H:O in carbohydrates?
1:2:1
What are the monomers of carbohydrates and what kinds of bonds do they form?
saccharides
Glycosidic bond
- Forms between the =O of one saccharide and hydroxyl (OH) group of another saccharide
- =O bond: Aldehyde or keton group
- aldehyde and ketones are just =O bonds, classified depending on where they are in the carbon chain
- ketone: R-(=O)-R
- aldehyde: R-(=O)-H
What is mono- vs di- vs oligo- vs poly- saccharides
Tells you how many saccharides there are in the sugar
True/False: We can attach sugars to other molecules
True:
- Proteins: Glycoproteins
- Lipids: Glycolipids
Why are lipids grouped together
They are hydrophobic
What are the three groups of lipids and what are they used for?
- Tricylglycerol: Used for energy storage (fats + oils)
- Steroids: Cholesterol which is found in animal cell membranes, precursor to steroid hormones
- phospholipids: component of membranes
What are the components of triglycerol?
- Three fatty acids: long chain of carbons with a carboxyl group at the end
- Glycerol (3- Carbon compounds with -OH groups attached to each carbon)
shape:
E, where each horizontal line is a fatty acid and the vertical one is the glycerol
- bond is between the -OH group and the carboxyl group
What is saturated vs unsaturated fatty acid?
saturated: no double bonds
unsaturated: has double bonds
