Biological Molecules Flashcards
What are the four categories of organic molecule?
Lipids, proteins, nucleic acids, and carbohydrates
Monomer
A single unit of a larger macromolecule
—Carbon based molecule
Polymer
The result of many monomers assembled as a group
Condensation/Dehydration Reaction
The process that links two monomers together with chemical bonds
—Occurs when two hydrogen and one oxygen atom (aka water) are removed from two monomers
Why is it called a “condensation” reaction?
Because when two monomers are linked together by a covalent bond, the result is a macromolecule plus a molecule of water
When water is being removed from monomers, we call it…
a dehydration reaction
Hydrolysis Reaction
Chemical reaction in which a water molecule is added
The type of chemical reaction responsible for linking monomers into polymers is known as…
condensation reaction
All polymers are linked by what type of bond?
Covalent
Type of chemical reaction responsible for breaking polymers back down into monomers..
hydrolysis reaction
Protein’s structure consists of
a repeating chain of amino acids
What are some functions of protein?
-Cellular Metabolism
-Transport Molecules
-Structure and Support
-Signaling Molecules
-Defense
-Movement
Amino acids are the monomers for…
protein (the polymer)
How many different kinds of amino acids are there?
Essentially 20
What is found in all amino acids?
A central carbon atom that bonds covalently to four different atoms/functional groups
The major difference between amino acids lies….
within the R-group/side chain
In an amino acid monomer, where is each component located?
Amino group on the left, carboxyl group on the right, carbon atom in the center, hydrogen atom on the top and side chain on the bottom
Name the components of an amino acid monomer.
-Central carbon atom
-Side chain
-Carboxyl group
-Hydrogen atom
-Amino group
R-group
Represents the part of the amino acid core structure that makes each of the 20 different amino acids unique
The properties of amino acids __ because their R-groups __
vary
What lay on the ends of an amino acid monomer?
N-terminus: amino group
C-terminus: carboxyl group
Peptide bond
Carbon-nitrogen covalent bond that results from the bonding between the n-terminus and the c-terminus of 2 amino acid monomers
Peptide vs polypeptide
Peptides generally have less than 50 amino acids linked together
Polypeptides generally have more than 50 amino acids linked together
Protein’s primary structure
Linear chain of amino acids
What do actin and myosin do?
Allow for movement as they are major components of muscle tissue
What does hemoglobin do?
Transports oxygen through the blood stream
What type of bonds form between the monomers that make up protein?
Peptide
What does a protein structure resemble?
A pearl necklace
What does a protein secondary structure resemble?
A piece of ribbon
What is an alpha helix
The part of the protein secondary structure that coils
What is a beta pleated sheet
The part of a protein secondary structure that loops back on itself
What does a proteins tertiary structure resemble?
A bunched up piece of ribbon
The secondary structure of a protein results from
Hydrogen bonds
Tertiary structure is not directly dependent on
Peptide bonds
Quaternary structure results from
Individual proteins coming together to form multi-subunit protein complexes
Nucleic acids consists of what kind of monomer?
Nucleotides
In order for a protein to be created, what needs to occur?
A single-stranded nucleic acid copy of the code stored in the DNA needs to be created (RNA)
What is RNA able to do that DNA cannot?
Leave the nucleus and interact with ribosomes in the cytoplasm
What is the process of RNA being made from DNA, to the creation of a protein known as?
Central Dogma of Molecular Biology
What is RNA?
A copy of the instructions stored in DNA that can be used to create a protein
What is the base structure of nucleic acids?
Phosphate group attached to the fifth carbon
Nitrogenous base attached to a carbon
Five-carbon sugar in the center
The major difference between nucleotides lies in the….
Exact type of sugar and nitrogenous base in the structure
What sugars are in the structures of DNA and RNA?
Deoxyribose and ribose (respectfully)
What is the telling difference between a DNA and RNA structure?
RNA has a hydroxyl group (OH) attached to a carbon, whereas DNA only has a hydrogen attached (H)
What is the difference between pyrimidines and purines?
Pyrimidines contain a single-ring structure
Purines are larger and have a two-ring structure
Which nitrogenous bases are contained by both DNA and RNA?
Cytosine, guanine, and adenine
Which nitrogenous bases are exclusive to either DNA or RNA?
DNA-Thymine
RNA-Uracil
How are nucleotides linked?
Between the sugar component and phosphate group of two separate nucleotides
The 3’ carbon is…
Always attached to the hydroxyl group
When two nucleotides polymerize….
a condensation reaction occurs and water is removed
What is a phosphodiester bond?
The covalent bond that results from a condensation reaction between the hydrogen atom of hydroxyl groups on the 3’ carbon and phosphate of a second nucleotide
Sugar-phosphate backbone
Continued covalent linkage of sugars and phosphates between nucleotide monomers
What are the tops and bottom of DNA and RNA strands?
Top: unlinked 5’ phosphate exposed
Bottom: unlinked 3’ hydroxyl
RNA is ____ whereas DNA is _____
single stranded; double stranded
What are the two strands of DNA held together by?
H-bonds
Hydrogen bonds in DNA only form between….
Guanine & cytosine, adenine & thymine
Complimentary base pairs
G-C and A-T groups
Antiparallel
The opposite alignment of two DNA strands
T or F: Nucleotides can be broken apart from a single strand of RNA by hydrolysis reactions.
True
Carbohydrates are polymers of
monosaccharides
What can carbohydrates be used for?
-Energy storage
-Structure/Support
-Cellular Identity
What is a monosaccharide?
A single, simple sugar molecule
Each monosaccharide consists of:
-Several hydroxyl functional groups
-Multiple carbon-hydrogen bonds
-A carbonyl functional group
Aldose monosaccharides
Have the carbonyl group attached to a terminal carbon
Ketose monosaccharides
Have a carbonyl group attached to an interior carbon
Glucose vs Galactose
Glucose’s hydroxyl group faces upwards, while galactose’s group faces downwards
Trioses
Three-carbon sugars
Pentose
Five-carbon sugar
Hexose
Six-carbon sugar
Polysaccharide
Another name for carbohydrates
Disaccharide
Two monomers in length
Glycosidic bond
Result of a condensation reaction between two monosaccharides
Carbohydrate chains can also take the appearance of….
A wall or branched chain
Which polysaccharide stores energy in animals?
Glycogen
Which polysaccharide is a structural component of bacterial cell walls?
Peptidoglycan
Which macromolecules are largely nonpolar and hydrophobic?
Lipids
Lipids are made up of….
A single glycerol molecule and more than one fatty acid molecule
What roles do lipids play in living organisms?
-Adjusting fluidity and solubility of cell membranes
-Storing energy
-Send chemical messages
Lipids are largely hydrophobic because
their structure contains a high number of hydrocarbons
Hydrocarbons are nonpolar because…
Electrons are shared equally in C-H bonds
Fatty acids consist of….
A carboxyl group and a hydrocarbon chain
Saturated vs unsaturated fatty acids
Saturated chains contain only single bonds
Unsaturated chains contain one or more double bonds
Fats
Nonpolar, composed of three fatty acids that are linked by a glycerol molecule
Ester bond
The bond created between glycerol and a fatty acid to produce a lipid
Phospholipid
Consists of glycerol and two hydrocarbon chains
Match the polymers with their bonds:
-Nucleic acids
-Proteins
-Lipids
-Monosaccharides
-Phosphodiester
-Peptide
-Ester
-Glycosidic
Protein Denaturation
The breaking down of weak bonds within a protein molecule, losing the non-primary structures
What do enzymes do?
Bring reactant molecules together for quicker biological chemical reactions
Enzymes
Act as catalysts for chemical reactions by lowering the activation energy
Activation energy
Amount of free energy required to reach the transition state (form new bonds)
Stages of enzyme action
Initiation, transition, termination
High temperatures and acidic pH effect enzymes because….
It destroys weak bonds and therefore the enzyme denatures
When enzymes are regulated; they are….
Turned off or in quickly by other molecules
Types of enzyme regulation
-
-
Competitive inhibitors
Compete with the substrate for the active site of the enzyme
Non-competitive inhibitors
Do not compete for the active site since they bind to another part of the enzyme
Allosteric Regulation
Changing of an enzymes shape due to a molecule bonding to the allosteric site
Cofactors
Non-protein molecules that help enzymes work
Coenzymes
Subset of cofactors that are organic
Which carbon is the carbonyl group attached to in fructose?
C2
How do we determine what number carbons are in a carbohydrate?
Count from end that is closest to the carbonyl group
What are the energy storage polysaccharides in plants and animals?
Starch and Glycogen
What is the difference between starch and glycogen structures?
Glycogen struture is more branched than starch structure
Cellulose structure consists of _____
chains of beta glucose molecules joined together by glycosidic and hydrogen bonds
The polysaccharide responsible for structure within fungi, insects and crustaceans
Chitin
The polysaccharide responsible for structure within bacteria
Peptidoglycan
Feedback inhibition
Enzymes work together in the metabolism of molecules within our cells
Feedback (negative) inhibition works to….
Stop the metabolic process once enough of a final substance has been made
How can you identify whether a nucleic acid is single or double stranded?
If there’s one phosphate, one nitrogenous base, and one sugar, it’s single-stranded
What pairing is perfect within the structure of DNA?
Purine & Pyrimidine together
A molecule of DNA is 20% C. What percentage of it is made up of G?
20% because they have to be equal amounts
A molecule of DNA is 20% C. What percentage of it is made up of T?
30%
Secondary RNA structure
C-G & A-U(?)
Adenosine Triphosphate (ATP)
Used to store energy
-Nitrogenous base attached to a sugar attached to three phosphate groups
Where is energy stored within an ATP?
Within the phosphate bonds
Breaking an ATP bond results in….
released energy
