Chapter 5 Flashcards
4 classes of large biological molecules
Carbohydrates, lipids, proteins, and nucleic acids
Macromolecules
Large molecules composed of thousands of covalently connected atoms
Polymers
Long molecules consisting of many similar building blocks
Monomers
Small repeating units that serve as building blocks for polymers
Dehydration Reaction
When two monomers bond together through the loss of a water molecule
Hydrolysis
When polymers are dissassembled to monomers reversing the dehydration reaction
Enzymes
Specialized macromolecules that act as a catalyst to speed up chemical reactions such as dehydration reactions and hydrolysis
Carbohydrates
Include sugars and polymers of sugars. (Monosaccharides, Disaccharides, and Polysaccharides)
Monosaccharides
The simplest carbohydrate, or single sugars.
Molecular formulas that are usually multiples of CnH2nOn.
Classified by their location of the carbonyl group (aldose or ketos) & number of carbons in the carbon skeleton
Carbohydrate Macromolecules
Polysaccharides, which are polymers composed of many sugar building blocks
Disaccharides
Formed when a dehydration reaction joins two monosaccharides.
Polysaccharides
Polymers of sugars, have storage and structural roles determined by its sugar monomers and the positions of glycosidic linkages.
Starch
A storage polysaccharide of plants - consists entirely of glucose monomers. (within chloroplasts & plastids)
Glycogen
A storage polysaccharide in animals. (within liver & muscle cells)
Cellulose
Polysaccharide that is a major component of the tough wall of plant cells. Alpha & Beta glucose rings.
Chitin
Structural Polysaccharide found in exoskeleton of arthhropods. Provides structural support of cell walls of many fungi.
Lipids
Do not form polymers. No affinity for water, they’re hydrophobic because they consist of hydrocarbons. Nonpolar covalent bonds.
The most biologically important Lipids
Fats, Phospholipids, and Steroids.
Fats
Constructed from glycerol and fatty acids
Glycerol
3 carbon alcohol with a hydroxyl group attached to each carbon.
Triacylglycerol
An ester derived from glycerol and three fatty acids
Saturated Fatty Acids
Have the maximum number of hydrogen atoms possible and no double bonds. Straight chains. Results in solids and found in animals.
Unsaturated fatty Acids
Have one or more double bonds. Forms bent chains. Results in liquid form and found in plants and fish.
Energy Storage
This is the main function of fats
Phospholipids
two fatty acids and a phosphate group are attached to glycerol
Phospholipid Bilayer
when phospholipids are added to water
Steroids
lipids characterized by a carbon skeleton consisting of four fused rings
Cholesterol
Important steroid which is a common component in animal cell membranes that allows for fluidity of membranes. Building block for other steroids including hormones.
Proteins
Biologically functional molecule that consists of one or more polypeptides. They account for more than 50% of the dry mass of most cells.
Enzymatic Proteins
Selective acceleration of chemical reactions (digestive)
Enzymatic Proteins
Selective acceleration of chemical reactions (digestive)
Defensive Proteins
Function: Protect against disease (Antibodies)
Storage Proteins
Function: Storage of amino acids
Transport Proteins
Function: Transport of substances
Hormonal Proteins
Function: Coordination of an organism’s activities (Insulin)
Receptor Proteins
Function: Response of cell to chemical stimuli
Contractile and motor proteins
Function: Movement
Structural Proteins
Function: Support
Poypeptides
Unbranched polymers built from the same set of 20 amino acids.
Amino Acids
Organic molecules with carboxyl and amino groups. Differing side chains (R groups)
Peptide Bonds
Amino acids are linked by these causing dehydration reaction
Functional protein
Consists of one or more polypeptides precisely twisted, folded, and coiled into a unique shape. This structure determines its function.
Primary structure of protein
The primary structure of a protein refers to the sequence of amino acids in the polypeptide chain. The primary structure is held together by peptide bonds that are made during the process of protein biosynthesis.
Secondary structure of protein
Consists of coils and folds in the polypeptide chain. Found in fibrous materials. Hydrogen bonds make these very strong. Spider Web.
“Tertiary” structure of protein
Determined by interactions between R groups rather than interactions between backbone constituents.
“Quaternary” structure of protein
Results when two or more polypeptide chains form one macromolecule. (Collogen: 3 polypeptides & Hemoglobin: 4 polypeptides)
Sickle-cell disease
Inherited blood disorder, results from a single amino acid substitution in the protein hemoglobin
Denaturation
The loss of a protein’s native structure caused by alterations in pH, salt concentration, temperature etc…
Chaperonins
Protein molecules that assist the proper folding of other proteins.
X-ray crystallography
Scientists use this to determine a protein’s structure. Another method is NMR
Nucleic Acids
These store, transmit, and help express hereditary information.
Gene
A unit of inheritance made of DNA, a nucleic acid made of monomers called nucleotides.
DNA
This provides direction for its own replication.
Polynucleotides
Nucleic acids that are polymers
Nucleotides
Polynucleotides made of monomers consisting of a nitrogenous base, a pentose sugar and one or more phosphate groups are called…
Nucleoside
The portion of a nucleotide without the phosphate group is called…
