Chapter 5 The Structure and Function Of Large Biological Molecules Flashcards
What are the four classes of large biological molecules that all living things are made up of?
Carbohydrates
Lipids
Proteins
Nucleic acids
Lipids are not polymers.
True or false?
True
A long molecule consisting of many similar building blocks called monomers
Polymer
What are the three of the four classes of life’s organic molecules that are polymers?
Carbohydrates
Proteins
Nucleic acids
How are polymers formed?
Condensation or dehydration reaction, a loss of a water molecule links monomers to form polymers
How are polymers broken down?
Hydrolysis, adds a water molecule that breaks a bond
The removal of a water to form a chemical bind is termed
Dehydration synthesis
Includes sugars and the polymers if sugars
Monosaccharides- single sugar
Disaccharides- 2 sugars
Polysaccharides-many sugars
Carbohydrates
Molecular formulas that are usually multiples of CH2O
(1-2-1 ratio)
Glucose (C6H12O6
Monosaccharides
How are monosaccharides classified?
- location of the carbonyl group (as arose or kerosene)
- number of carbons in the carbon skeleton
- Simplest sugars
- Major fuel for cells and as raw material for building molecules
- ring or linear structure
Monosaccharides
In aqueous solution monosaccharides form ________
Rings
What is a glycosidic linkage?
When disaccharides are made by dehydration reaction
The structure and function of a polysaccharide are determined by its _________
Sugar monomers and the position of glycosidic linkages
Is amylose or amylopectin beached?
Amylopectin
Is cellulose alpha or beta glucose?
Beta
Storage polysaccharide of animals
Glycogen
Starch in plants
Where do humans store glycogen?
Liver and muscles
Which polysaccharide has the greatest number of branches?
Glycogen
The three categories of fats
- phospholipids
- triglycerides
- steroids
- large biological molecules that do not form polymers
- composed predominantly of hydrogen and carbon atoms
Fats
Formed by bonding glycerol to three fatty acids
Joined by dehydration or condensation reaction
Broken apart by hydrolysis
Triglycerides
Two types of fatty acids
Saturated and unsaturated
All carbons are linked by single covalent bonds
Maximum number of hydrogen atoms possible and NO DOUBLE BONDS
Saturated fatty acid
- Has one or more double bonds
- double bonds cause the tail to bend, so it is liquid at room temp.
- cis fats forms naturally
- Hydrogens are on the same side of the double bond
Unsaturated fatty acids
-glycerol, 2 fatty acids and a phosphate group
-Amphipathic molecule
-phosphate region- polar, hydrophilic, head
-fatty acid chains- nonpolar, hydrophobic,
tail
Phospholipid
When ________ are added to water, they self-assemble unit a bilayer, with the hydrophobic tails pointing towards the interior
Major component of all cell membranes
Phospholipid
- **four interconnected rings of carbon atoms
- usually not water soluble
- cholesterol- important component in animal cell membranes
Steroids
Lipids cannot be considered polymers because….
They are not composed of monomer subunits
All ______ do not dissolve well in water.
Lipids
Compared to tropical fish, arctic fish oils have…..
More unsaturated fatty acids
Decrease in chain length In colder environments
Proteins account for more than ____% it the dry mass of most cells
50
Protein functions include:
- proteins involved in gene expression and regulation
- Motor proteins
- defense proteins
- metabolic proteins
- cell signaling proteins
- structural proteins
- transportation
- storage proteins
- Organic molecules with carboxyl and amino groups
- differ in their properties due to differing side chains, called R groups
- cells use 20 amino acids to make thousands of proteins
Amino acid monomers
Polypeptides are __________ _________ built from the same set of 20 amino acids
Unbranched polymers
- Joined by dehydration or condensation reaction
- peptide bond
- forms polypeptides
- proteins are made up of 1 or more
- broken apart by hydrolysis
Polypeptides
Each polypeptide has a unique linear sequence linear sequence of amino acids, with a ________ end (C-terminus) and an ________ (N-terminus)
Carboxyl, amino
The sequence of amino acids determines a protein’s ______________
And this determines its function
Three-dimensional conformation
Four levels of protein structures
- primary
- secondary
- tertiary
- quaternary
All polypeptides have primary primary, secondary, and tertiary
Quaternary structure is not present in all polypeptides
What is the primary structure of proteins?
Amino acid sequence and this is determined by genes
secondary structure of proteins
- chemical and physical interactions course folding
- repeating patterns-result form hydrogen bonds between repeating constituents of the polypeptide backbone
- alpha helices-coil
- beta pleated sheets- folder structure(key determinants of a protein’s characteristics
- “random coiled regions” (not a helix or beta pleated sheet, shape is specific and important to function)
Tertiary structure of proteins
- folding gives complex three-dimensional shape
- final level of structure for single polypeptide chain
Tertiary structure is determined by interactions between ________, rather than interactions between the backbone constituents
These interactions included……
Strong covalent bonds called ___________ may reinforce the protein’s structure
R group
Hydrogen bonds, ionic bonds, hydrophobic interactions*, and van der Waals interactions
disulfide bridges
Quaternary structure
Made up of 2 or more polypeptides from on macromolecule
- protein subunits- individual polypeptides - multinumeric proteins- protein’s with multiple parts
What are factors promoting protein folding and stability?
1 hydrogen bonds 2 ionic bonds and other polar interactions 3 hydrophobic effects 4 Van der Waals forces 5 disulfide bridges
The loss of a protein’s native conformation is called
Becomes biologically inactive
Denaturation
What cause a protein to unravel?
Alterations in pH, salt concentration, temperature, or other environmental interactions
Something that helps other proteins fold
Chaperonins
What biological molecules contain peptide bonds?
Proteins
What are the two classes of nucleic acids?
Deoxyribonucleic acid (DNA)- double stranded, store genetic information
Ribonucleic acid (RNA) -single stranded, involved in decoding this information into instructions for linking together a specific sequence of amino acids to forms polypeptide chain
Nucleic acids are polymers called ____________
Polynucleotides
Each polynucleotide is made of monomers called _________
Nucleotides
Describe the structure of nucleic acids
Monomer linker into polymer with a sugar-phosphate backbone
Nucleoside?
(Not the phosphate base)
-nitrogenous base
-sugar
Ribose
DexoriboseWhat are the two families of nitrogenous bases?
Pyrimidines
-single six-membered ring
Purines
- a six-membered ring fused to a five- membered ring
- adenine and guanine (double ring)
Complementary base pairings
A=T
G triple bond to C
In the DNA double helix backbones run in opposite 5’ to 3’ directions from each other, an arrangement referred to as…..
Antiparallel
When you see phosphate group it’s at _____
And the opposite end is the hydroxyl group at _____
5’
3’
Thymine is associated with? And uracil?
DNA, RNA
How many forms of DNA? RNA?
1 form, several forms
2 strands DNA are bonded by HYDROGEN BONDS. There’s bonds are called __________
Phosphodiester bonds
_______ encodes hereditary information
DNA, not RNA
