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What is a hydrogen bond ?
a weak bond between a proton and an electronegative atom
Where are hydrogen bonds found in water?
bonds between H in one water molecule and O in another water molecule
Where are hydrogen bonds found in DNA?
between nitrogenous bases
How many hydrogen bonds are found between each complementary base pairing?
2 between A & T and 3 between C & G
What is the structure of an amino acid?
Amino group (N-terminus), Carboxyl group (right side), Side chain (R-group)
What are the three options for the R group?
polar, nonpolar, charged
For each R group option, describe the polarity and justify your response
Polar folds out because it is hydrophilic and is attracted to the water
Nonpolar folds in because it is hydrophobic and is "afraid" of the water
Charged folds out because it is hydrophilic and is attracted to the water
What are three properties of water?
Polar
Excellent solvent
High heat capacity
High heat of vaporization
Cohesion
Adhesion
Less dense as a solid rather than a liquid
How does hydrogen bonding allow polarity?
Differences in electronegativity result in partial charges which are used to make hydrogen bonds.
How does H bonding allow a high heat capacity?
When heat is absorbed, hydrogen bonds are broken and water molecules can move freely. When the temperature of water decreases, the hydrogen bonds are formed and release a considerable amount of energy
How does H bonding allow a high heat of vaporization?
: As a result of the network of hydrogen bonding present between water molecules, a high input of energy is required to transform one gram of liquid water into water vapor, an energy requirement called the heat of vaporization
How does H bonding allow for cohesion?
holds hydrogen bonds together to create surface tension on water.
Adhesion: in the case of water this is caused by hydrogen bonding. In liquid water each molecule of water is attracted in all directions to perhaps as many as four other water molecules through hydrogen bonding
How does H bonding create a less dense solid rather than liquid?
In liquid water hydrogen bonds form and break constantly, in ice (solid water) hydrogen bonds remain stable and the water forms a crystalline structure keeping the water molecules farther apart making it less dense than water.
Describe why water is considered a polar molecule?
There is a difference in electronegativity between the O and the H's. The O is more electronegative and thus pulls the shared electrons closer to it resulting in a polar covalent bond between each H and the O.
Using the properties of water, describe how water can move up a capillary tube to move from the roots to the leaves in a plant.
cohesion - water attracted to other water molecules
adhesion - water attracted to the polar components of the xylem
Using the properties of water, describe how a water strider can walk on water.
surface tension - water molecules attracted to one another creates a "surface" to the water
Also, the water strider evenly distributes its weight to not break that surface.
What are the four macromolecules?
Proteins, Lipids, Carbs, Nucleic Acids
What are the elements found in a carbohydrate?
carbon, hydrogen, oxygen
What are three functions of carbohydrates in living organisms?
Quick Energy, Structure (chitin and cellulose), Energy Storage
What are the elements found in a protein?
Carbon, Hydrogen, Oxygen, Nitrogen
What are the functional groups found in all amino acids?
Amino group, Carboxyl group, R group
What are three functions of proteins in living organisms?
Metabolism, Support, transport
What are the elements found in nucleic acids?
Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus
What are parts found in all nucleotides?
phosphate, sugar, nitrogenous base
What are three functions of nucleic acids in living organisms?
Storage of genetic information ( DNA, RNA); transfer of info from DNA to cell (RNA) andenergy storage/release (ATP)
What are the elements found in a lipid?
Carbon, Hydrogen, Oxygen
How are the three different types of lipids different?
Triglycerides: stored fat
Cholesterol: bile, hormones and Vitamin D
Phospholipids: Lipid bilayer
What are three functions of lipids in living organisms?
Hormones (Steroids), Membrane structure, long term energy storage (fats), Insulation, waxes
Which macromolecule(s) contain nitrogen?
Protein and Nucleic Acids
Which macromolecule(s) contain phosphorus?
Nucleic Acids
Which macromolecule(s) contain sulfur?
Proteins
How does the R group affect the folding of the protein? (include polar and nonpolar R groups)
depending whether the R group is hydrophobic (nonpolar) or hydrophilic (polar). Protein folding results from hydrophilic R groups positioning themselves near other hydrophobic R groups and away from hydrophilic R groups and the cytoplasm
What is dehydration?
removal of water molecule to join two subunits
What is hydrolysis?
Water molecule is added to break two subunits apart
What type of bond is found in carbohydrates?
Glycosidic Bond
Where is a glycosidic bond located?
In between two monosaccharides (H + OH)
What type of bond is found between protein monomers?
peptide bond
Where is a peptide bond located?
in between two amino acids (C-terminal and N-terminal)
What type of bond is found between nucleic acid monomers?
Phosphodiester Bond
Where is a Phosphodiester Bond located?
Between phosphate of one nucleotide and sugar of another (P is bonded to the 3 carbon of one sugar and 5 carbon of next sugar)
What is the monomer of a carbohydrate?
monosaccharide
What is the monomer of a protein?
amino acid
Components of an amino acid
Central Carbon, Amino group, Carboxyl group, R group
What is the monomer of a nucleic acid?
nucleotide (sugar, phosphate, nitrogen base)
Identify the components of a phospholipid
polar head (hydrophilic) and nonpolar tail (hydrophobic)
What type of bond is found in starch?
α 1,4 Glycosidic bonds
What type of bond is found in cellulose?
β 1,4 Glycosidic bonds
Which bond can be broken by animals?
α 1,4 Glycosidic bonds
DNA vs. RNA
DNA: deoxyribose sugar, thymine, double strand
RNA: ribose sugar, uracil, single strand
How does a saturated and unsaturated fatty acid differ?
Unsaturated: has one double bond causing a kink
Saturated: Carbons are saturated with Hydrogens; a single bond
How does the level of saturation affect the function of the lipid?
Saturated are solid at room temperature- stackable
Unsaturated are liquid at room temperature; pack less tightly
Describe how a nonpolar to polar R group substitution changes the structure and function of a protein
Depending on whether the R group is hydrophilic or hydrophobic Interaction between hydrophobic amino acids with each other and hydrophilic amino acids with each other result in folding that gives the protein its 3D shape. Changing a nonpolar R group to a polar R group can change the 3D shape of the protein and therefore change its ability to function correctly.
Describe how a cytosine to thymine substitution changes the structure and function of DNA
They have a different number of bonds required to bind to their complementary base so the connection between the Guanine and the Thymine would be unstable
Changing a C to a T changes the genetic code for a protein and can result in a nonsense or missense mutation that can lead to a nonfunctional protein/genetic disorder.. Ex A to T substitution in the hemoglobin gene results in Sickle cell anemia.
Describe how a cytosine to guanine substitution changes the structure and function of DNA
They have a different number of bonds required to bind to their complementary base and they have different numbers of rings so the width of the DNA would be impacted. It would be wider where the Guanine is added.
Describe how a deoxyribose to ribose changes the structure and function of a nucleic acid
he change would cause the nucleic acid to function as a RNA molecule. The purpose of RNA is to develop proteins within our body through the process of protein synthesis. RNA is also single stranded whereas DNA is double stranded.
Describe the structure of the nucleic acid polymer
DNA has a double-helix structure The sugar (deoxyribose) and phosphate lie on the outside of the helix, forming the backbone of the DNA. The 2 strands run in opposite directions (antiparallel) The nitrogenous bases are stacked in the interior, like the steps of a staircase, in pairs. Adenine and Thymine/ Cytosine and Guanine are bound to each other by hydrogen bonds.
What are the ends called and what is found at each end?
5' and 3' ends; If carbons in deoxyribose are numbered starting with C attached to nitrogenous base, #3 carbon is closest to 3' end and #5 carbon is closest to 5' end
Which end is the location of the growing nucleic acid strand?
3'
What are the complementary base pairings found in nucleic acids?
A bonds with T; C bonds with G
Identify the number of hydrogen bonds found between these two nitrogenous bases
Adenine and Thymine: two hydrogen bonds
Cytosine and Guanine: three hydrogen bonds
Primary level of folding
The sequence of amino acids; covalent peptide bonds
Secondary level of folding
Folding of the protein: Alpha Helix or Beta Pleated Sheet; hydrogen bonds
Tertiary level of folding
3D structure of a protein. Is created due to the interactions between the R groups of the amino acids; ionic Bonds, Hydrogen bonds, Hydrophobic interactions, disulfide bridges
Quaternary level of folding
Many proteins are made up of a single polypeptide chain and have only three levels of structure; hydrogen and disulfide bonds
What are the ends of a protein called and what is found at each end?
Amino group is found at the N terminus; a carboxyl group is found at the C terminus
Which end is the location of the growing polypeptide strand?
Amino group of incoming amino acid reacts via dehydration synthesis and joins with the carboxyl group of existing chain
Describe the structure of a carbohydrate polymer.
Carbohydrates are molecules that are made of two or more simple sugars. They are polymers made of a ratio of 1 carbon, 2 hydrogen, and 1 oxygen atom. They also have an hydroxyl group.
What are the components of a fat molecule?
glycerol backbone(three carbon atoms, five hydrogen atoms and three hydroxyl groups) and fatty acids
What are the components of a phospholipid?
Phospholipids consist of a glycerol molecule, two fatty acids, and a phosphate group that is modified by an alcohol. The phosphate group is the negatively-charged polar head, which is hydrophilic. The fatty acid chains are the uncharged, nonpolar tails, which are hydrophobic.
Describe the structure of a steroid
Fused ring structure. Four linked carbon rings.
Note
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