Chapter 5: The Structure and Function of Large Biological Molecules
There's a few terms missing that are in the slides... I wanna wait for the professor to explain them lol! I'll add them after the Chapter 5 lecture(s)
Terms in this set (83)
What are the four classes of large biological molecules?
Carbohydrates, Lipids, Proteins, Nucleic Acids
What do carbohydrates do?
serve as fuel and building material
What are lipids?
diverse group of hydrophobic molecules; think "fats"
What are Proteins? What do they do?
proteins contain very diverse structures that span a wide range of function
What do nucleic acids do?
store, transmit, and help express hereditary information
Polymers that are built from monomers
What type of molecules are macromolecules?
carbohydrates, proteins, nucleic acids
a long molecule consisting of similar or identical building blocks linked by covalent bonds
the repeating units that serve as the building blocks of the polymer
What are Monomers?
monosaccharides, amino acids, nucleotides
What are Polymers?
polysaccharides, polypeptides (aka proteins), polynucleotides (aka DNA or RNA); each class of polymer is formed from a specific set of monomers
the removal of a water molecule between an monomer and short polymer to form a longer molecule
specialized proteins that speed up chemical reactions
when the bond between monomeres is broke by adding a water molecule, with a hydrogen from water attaching to one monomer and the hydroxyl group (OH) attaching to the other; hydrolysis adds a water molecule, breaking a bond
Why are lipids different from other macromolecules?
Lipids do not form polymers because they are hydrophobic
Why are lipids hydrophobic?
lipids are hydrophobic because they consist of mostly hydrocarbons, which form nonpolar covalent bonds
Three Lipids that are relevant to Biology
fats, phospholipids, steroids
What are fats?
fats are large molecules assembed from smaller molecules by dehydration reactions. They are constructed from two smaller molecules: Glycerol, Fatty acids
What do fats do?
a long carbon skeleton where the carbon at one is is part of a carboxyl (R-COOH)
has no double bonds between carbon atoms in the hydrocarbon chain
has one of more double bonds in the hydrocarbon chain; cis-double bonding causes bending
major constituent of cell membranes, constructed of a polar head and hydrocarbon tails; important from function in cell membraines
What do phospholipids do?
phospholipids assember into bilayers in an aqueous solution; tails are interior (pointing away from water) and the heads touch the water
What are phospholipids made of?
Gycerol backbone, two fatty acid chains (hydrophobic), a phosphate group and a head group (head group type varies)
lipids characterized by a carbon skeleton consisting of four fused rings
Common Steroid in animal cell membranes; base of vetebrate sex hormones (think estradiol and testosterone)
Sugars and polymers of sugars
What are Monosaccharides?
monosaccharides are the simples sugars that can be used for fuel or be converted into other organic molecules; can be combined to formed polymers
Disaccharides and Polysaccharides
can be used as both energy storage and as a structural component
Criteria for classifying sugars
1. Position of the carbonyl (R-CO) group
2. Size of the carbon skeleton (ranges from 3-7 carbons long)
3. Spatial arrangement of groups around asymmetric carbons
Sugars in an aqueous solution
most 5-carbon or 6-carbon sugars from rings in an aqueous solution
disaccharides consist of two monosaccharides joined by glycosidic linkage
a covalent bond formed between two monosaccharides by a deydration reaction (removal of H2O to connect monomers to polymers)
polymers with a few hundred to a few thousand monosaccharides joined by glycosidic linkages
What do polysaccharides do?
store sugars (i.e starch), serve as building material from structures that protect the cell (i.e. cellulose in plants)
Consist of glucose monomers and are the major storage form of glucose in plants
Consists of glucose monomers and is a major structural component of cell wall in plants
polymers of amino acids; a biologically functional molecule made up of one or more polypeptides that are folded into specific three-dimensional structures
What's another name for proteins?
How many different types of amino acids are there?
Amino Acid Classification
amino acids can either be non-polar, polar, acidic (negatively charged) or basic (positively charged)
What is the function of a protein?
Proteins are folded polypeptides. The function of a protein is determined by its shape or conformation
The Four Levels of protein structure
Primary, Secondary, Tertiary (which is determined by interactions between side chains of amino acids), Quaternary
Organic molecules posessing both caryboxyl (R-COOH) and amino (R-NH) groups
Amino Acids II
all amino acids share a common structure but differ in their proerties due to differing side chains (attached to the shared asymmetric carbon)
the bond that is the result of amino acids joining from a dehydration reaction; the process is repeated over and over again to make the polypeptide
Polypeptides have a unique linear sequence that is determinded by the order of the side chains
Primary Protein Structure (1°)
the sequence of amino acids, read from N-terminus to C-terminus
Secondary Protein Structure (2°)
Hydrogen bonding of the peptide backbone that causes the amino acids to fold into a repeating pattern
Tertiary Protein Structure (3°)
three-dimensional folding pattern of a protein due to side chain interactions
Quaternary Protein Structure (4°)
protein consisting of more than one amino acid chain
What is Sickle-Cell Disease?
an inherited blood disorder that is the result from a single amino acid substitution in the protein hemoglobin
Why is protein structure important?
A slight change in primary structure can affect a protein's structure and ability to function
What determines protein structure?
physical and chemical conditions, like altered pH, salt concentration, temperature
the loss of a protein's native (original) structure; a denatured protein is biologically INACTIVE.
protein molecules that assist the proper folding of proteins
What type of diseases are associated with misfolded proteins?
Alzheimer's, Parkinson's and Mad Cow Disease
How do chaperonins assist the folding of proteins?
1. the unfolded polypeptide enters from the top of the hollow cylinder
2. the cap attaches, creating a hydrophillic environment that allows the polypeptide to fold
3. cap comes off, correctly folded protein is released
store and transmit hereditary information; the sequence of bases along a nucleotide polymer is unique/different for each gene
What are the two types of nucleic acids?
Deoxyribonucleic acid (DNA), Ribonucleic acid (RNA)
Deoxyribonucleic Acid; provides directions for its own replication; directs synthesis of messenger RNA (mRNA) and through the mRNA, controls protein synthesis
the amino acid sequence of a polypeptide is programmed by a gene
units of inheritance that are made of nucleic acids; serves as a code for RNA to make proteins (mRNA); need for functional RNAs
Where does protein synthesis occur?
The process of DNA directing the synthesis of mRNA to control protein synthesis on ribosomes
What is the flow of genetic information?
DNA → RNA → Protein
A polymer composed of nucleic acids
monomers that compose each polynucleotide
What are nucleotides made of?
a nitrogen base, a pentose sugar, and one or more phosphate groups
the portion of a nucleotide WITHOUT the phosphate group; just the nitrogenous base and sugar
Two families of Nitrogenous Bases
Pyrimidines and Purines
Cytosine, Thymine and Uracil; each have a single six-membered ring
Adenine and Guanine; hae a six-membered ring fused to a five-membered ring
What is the sugar in DNA?
What is the sugar in RNA?
nucleoside (nitrogenous base and sugar) + phosphate group
Nucleotide polymers are linked together to construct a polynucleotide; adjacent nucleotides are joined by covalent bonds
Nucleotide Polymers II
the covalen bonds formed by adjacent nucleotides create the backbone of sugar-phosphate units with nigrogenous bases as the appendages; the sequence of bases along DNA or mRNA polymers is unique for each gene
What is the structure of RNA molecules ?
RNA molecules usually exist as a single polynucleotide chain (linear chain)
What is the structure of DNA molecules?
a double helix, containing many genes; DNA molecules have two polynucleotides spiraling around an imaginary axis, forming the double helix
in the DNA double helix, the two backbones (polynucleotides) run in opposite 5' → 3' directions from each other