Chapter 2.7 and 2.8
Chapter 2.7
CLaPiN acronym for four major classes of macromolecules
Carbohydrates
Lipids
a
Proteins
i
Nucleic acids
Biological Macromolecules are large organic molecules that are synthesized by the human body. Elements ALWAYS contain carbon, hydrogen and oxygen. Some may also have one or more of the following: Nitrogen Phosphorus or sulfur. Remember by the acronym CHON P.S.
The carbon component of biological macromolecules may simply be an individual carbon atom or numerous carbon atoms arranged in a carbon skeleton as a chain ,branch or ring.
Chapter 2.7
A single carbon atom or a carbon skeleton can have only hydrogen atoms attached, called hydrocarbons. Hydrocarbons are nonpolar molecules because they contain only C-C and C-H bonds.
Hydrocarbons are hydrophobic and methane gas (CH4) is an example of a hydrocarbon
Functional Group is a group of two or more atoms that, when present together on molecule
Functional groups include hydroxyl (-OH), carboxyl or carboxylic acid (-COOH), amine (-NH2) and phosphate (PO43-). Each functional group is polar and able to form hydrogen bonds increasing the molecule's solubility in water. Functional groups may act as an acid and release H+ such as carboxylic. Whereas others may act as a base by binding H+ such as an amine group.
Polymers are large molecules made up of smaller repeating units. Monomers is identical or similar molecules that repeat within a polymer
Some Carbohydrates, nucleic acids, and protein are polymers (glycogen,starch)
Lipids are not polymers
Carbohydrate polymers contain sugar monomers, nucleic acids have nucleotide monomers, and proteins are composed of amino acid monomers.
Two monomers bonded together are DIMER
Dehydration Synthesis is a chemical reaction that joins small molecules together by removing a molecule of water aka condensation
Hydrolysis is where water splits a larger molecule into smaller parts
Lipids- diverse group of nonpolar, water-insoluble (hydrophobic) molecules that function as stored energy, components of cellular membranes, and hormones. Triglycerides, phospholipids, steroids, and eicosanoids are 4 primary classes of lipids.
Triglycerides are the most common form of lipids in live organisms. It is used for long term energy storage in adipose connective tissue and for structural support, cushioning, and insulation of the body. EX ; insulates the abdomen against heat loss
Glycerol is a chemical component of both triglyceride and phospholipid molecules. It also is a 3 carbon molecule with hydroxyl functional group attached to each carbon.
Fatty Acid is composed of a long chain of hydrocarbons with a carboxylic acid functional group at the end.
Triglycerides are formed by the process of dehydration synthesis during which the equivalent of a water molecule is lost for each fatty acid added to the glycerol.
Fatty acids may vary in length ranging from 14 to 20 carbons.
Saturated Fatty Acid lacks double bonds, every caarbon has the maximum number of hydrogen atoms bound to it.
Unsaturated Fatty Acid has one double bond and Polyunsaturated Fatty Acid has two or more double bonds.
Lipogenesis is the formation of triglycerides from glycerol and fatty acids, excess nutrients the adipose connective tissue binds fatty acids to glycerol to form triglycerides in dehydration synthesis
Lipolysis on the other hand is when the adipose connective tissue breaks down triglycerides and releases the products into the blood when nutrients are needed.
Phospholipids basically are fat-like molecules formed the main building blocks of every cell membrane. The head contains a polar phosphate group (choline, ethanolamine, or the amino acid serine) which is hydrophilic while the tails consist of 2 fatty acid chains which are hydrophobic.
Steroids hormones are lipid derived chemical messengers synthesized from cholesterol that regulate metabolism, immune response and reproductive functions. May obtain from eating animal products such as meat, eggs, and milk.
Eicosanoids short distance chemical messengers. Modified 20 carbon fatty acids that were obtained from phospholipid plasma membranes. Four classes include prostaglandins, prostacyclins, thromboxanes, and leukotrienes. These are signaling molecules. Primary function in the inflammatory response of the immune system and communication within the nervous system.
Glycolipids are lipid molecules with an attached carbohydrate. Has many roles including cellular recognition to form tissues. Fat-soluble vitamins, which are vitamins A,D,E, and K
Lipid molecules do not dissolve in water they are more than likely non polar structures with hydrocarbon chains
Characteristics that allows phospholipids to do there job is possessing both hydrophilic and hydrophobic regions which allows them to from the lipids bilayer of cell membrane
Carbohydrate means hydrated carbon. It is made up of carbon, oxygen, and hydrogen.
The number of carbon atoms typically range from 3 to 7. The least complex carbohydrates are simple sugar monomers called monosaccharides and also have between 3 to 7 carbon atoms.
Disaccharides basically are 2 sugars. Provide quick energy for the body. They dissolve easily in water. The body must break down into single sugars before your cells can use them.
Polysaccharide is a class of carbohydrates composed of 3 or more sugars
Monosaccharide example - galactrose, fructose and glucose
Disaccharide - sucrose, lactose and maltose
Polysaccharides - starch and glycogen
Glucose is 6 carbon carbohydrates.
Glucose is crucial to life processes because it is the primary nutrient supplying energy to cells.
Blood glucose must be carefully maintained by homeostatic systems to ensure a continual, adequate energy supply for cellular activities.
Liver and skeletal muscle tissue absorb the excess glucose from the blood and then bind the glucose monomers together to form a polysaccharide called glycogen by a process called glycogenesis
Glycogenolysis is the breakdown of stored glycogen into glucose to supply energy.
Gluconeogenesis happens mostly in the liver. The metabolic process by which your body makes new glucose from non-carbohydrate sources such as amino acids, lactate and glycerol.
RIbose and deoxyribose are composed of five carbon monosaccharides called pentose sugars and are also structural components of nucleic acids. The only structural difference between the pentose sugars is the lack of an oxygen atom on carbon two of the deoxyribose sugar.
Cellulose is a structural polysaccharide of plant cells that cannot be digested by humans because of the unique chemical bond.
Glycosaminoglycans (GAGs) is a special molecule in your body that act like a sponge that holds water and gives structure to your skin joints and tissues
They are also attached to a protein form proteoglycans. Both of these are types of molecules associated with ground substance composing connective tissue.
Nucleic Acids are biological macromolecules within cells that store and transfer genetic or hereditary information. Normally found within the cell nucleus. They determine the type of proteins synthesized within cells.
DNA and RNA are polymers composed of nucleotide monomers. Nucleotide is basically the building blocks of DNA and RNA composed of a nitrogenous base, a phosphate group and a sugar.
Phosphodiester bond is the strong chemical link that holds individual nucleotides together to form the backbone of DNA and RNA.
Sugar is a five carbon pentose sugar (ribose for RNA and deoxyribose for DNA)
Nitrogenous Base has either a single-ring or a double ring structure that contains both carbon and nitrogen within the ring.
Single nitrogenous based are called Pyrimidines (include cytosine, uracil and thymine)
Double ring nitrogenous bases are called Purines. (include adenine and guanine)
Rubonucleic Acid (RNA) is a single stranded nucleic acid located both within the cell nucleus and within the cytosol of the cell.
Nucleotides that are part of RNA molecules called ribonucleotides, are composed of a ribose sugar, phosphate and four nitrogenous bases : cytosine, uracil, adenine or guanine.
The sugar phosphate aka backbone of the single stranded RNA molecule. The phosphodiester bonds linking the ribonucleotides composing the RNA polymer, and the four types of nitrogenous bases (C, U, A, and G) within RNA molecules.
Deoxyribonucleic Acid (DNA)- double stranded nucleic acid, it is a component of chromosomes. A small, circular strand of DNA is also within mitochondria.
DNA called deoxyribonucleotides, have deoxyribose sugar, a phosphate, and one of four nitrogenous bases: cytosine, thymine, adenine or guanine.
The double strands of nucleic acid are held together by hydrogen bonds formed between complementary nitrogenous bases: thymine with adenine and guanine with cytosine.
Adenosine triphosphate or ATP is composed of the nitrogenous base adenine and a ribose sugar and 3 phosphate groups covalently linked to adenosine. (used within high intensity energy fueled) ATP is the central molecule in transfer of chemical energy within cells.
ATP is a fully charged battery that provides usable energy while ADP is a partially discharged battery that needs to be recharged. ATP releases energy ADP recharging energy.
Nicotinamide Adenine Dinucleotide (NAD+) and Flavine Adenine Dinucleotide (FAD) are helper molecules (coenzymes) that your cells use to move energy around during cellular respiration. Help turn food you eat into energy.
Approx. 50,000 different proteins are synthesized (produced) by cells, and that proteins account for about ⅕ of the human body weight. Proteins function within a cell, a plasma membrane (the cell boundary) or blood plasma and other body fluids.
Protein structure is a large complex molecule made of smaller building blocks called amino acids.
Composed of one or more linear strands of amino acid monomers that may number in the thousands.
Amino Acids linked by Peptide bonds that form dehydration synthesis reactions between the amine functional group of one amino acid. Basically a strong chemical link that joins amino acids together to build proteins.
A dimer composed of two amino acids, which are linked by peptide bond is a dipeptide
Oligopeptide is a strand of small amino acids between 3 and 20
where a larger strand of amino acids may be referred to as a polypeptide or a protein. (more than 20)
Proteins with carbohydrates attached are called glycoproteins.
The glucocalyx of cells is composed of both glycoproteins and glycolipids. Used to identify the cell as self.
R (remainder) groups distinguish different amino acids from one another. Properties of the R groups form the basis for classifying amino acids.
Chapter 2.8
Nonpolar Amino Acids contain R groups with either hydrogen (glycine) or hydrocarbons (alanine, valine, isoleucine, leucine, phenylalanine, and tryptophan) group with other nonpolar amino acids by hydrophobic interactions
Polar Amino Acids contain R groups with elements in addition to carbon and hydrogen. (serine, threonine, asparagine, glutamine, and tyrosine.
Charged Amino Acids can have either a negative charge or a positive charge. Negatively charged R groups include glutamate and aspartate, positively charged R groups include histidine, lysine, and arginine. Ionic bond can form between an R group with negative charge and an R group with a positive charge. Polar or charged are hydrophilic
Amino Acids with Special Functions - three amino acids (proline, cysteine and methionine) have unique characteristics. The R group in proline attaches to the amine group, forming a ring.
The Sulfhydryl functional groups of two cysteine amino acids form disulfide bonds.
Disulfide bonds are covalent bonds that stabilize the folding of a protein.
Methionine is always the first amino acid positioned when a protein is synthesized.
We describe a protein as being composed of a linear sequence of amino acids that are bonded together through covalent peptide bonds. This sequence is called its primary structure.
Proteins then fold to form into its 3D shape or conformation. Conformation is important for it so it can properly function.
The process of protein folding is assisted by specialized proteins called chaperones that “direct” the folding process.
Intramolecular Interactions:
Hydrogen Bonds (velcro) - weak attraction between slightly positive hydrogen atoms and slightly negative oxygen or nitrogen atoms. Thousands work together like velcro to hold the proteins main coils and sheets in place.
Ionic Bonds salt bridges (the magnets) - electrical attraction between fully charged positive and negative sections of the protein, just like opposite poles of magnets these opposite charges lock together to lock specific loops of the protein in position.
Hydrophobic Interactions (the introverts) - hydrophobic parts of protein to hide from the watery environment of the body, retreat to inside of the protein structure focing the hydrophilic section outside.
Disulfide Bridges (superglue)- strong permanent covenant bonds that form between 2 sulfur atoms on specific amino acids (cysteine), the strongest bond of them all it acts like super glue stabilizing final shape so protein doesn't easily unravel under heat or stress.
The 2 distinctive secondary structures are a spiral coil called alpha helix and a planar pleat arrangement called beta sheet
Alpha Helix gives some elasticity (ability to return to original shape following compression or stretch) to fibrous proteins that are located for example skin or muscle
Beta Sheets give some degree of flexibility to many globular proteins
Tertiary Structure is the final 3D shape exhipted by one completed protein chain. 2 categories of proteins either globular or fibrous are distinguished by their molecular shape.
Globular Proteins - fold into compact, often nearly spherical shapes such as enzymes, antibodies, and some hormones.
Fibrous Proteins - are extended linear molecules such as the cytoskeleton and actin and myosin contractile proteins within muscle cells.
Quaternary Structure- protein is present only in those proteins with 2 or more protein strands.
The protein hemoglobin is an example because it is composed of four protein chains.
Prosthetic Group - is a nonprotein structure covalently bonded to the protein.
Biological activity of a protein is usually disturbed or terminated when its conformation (or structure) is changed. This change in protein confirmation is called denaturation.
The tertiary structure of the protein is disrupted if the protein is heated or chemically altered.
This increase weakens the intramolecular interactions that hold the protein in its 3d shape.
Denaturation may take place in response to changes in pH. Common causes are heat, pH changes, chemicals, mechanical agitation.
Changes in blood pH out of the normal range can be lethal because of the denaturation of protein structure and accompanying loss of function.
Structure of Protein
Primary structure- the linear sequence of amino acids in protein
Secondary structure- structural patterns within protein that results hydrogen bonds formed between amino acids, include alpha helixes and beta sheet
Tertiary Structure- final 3D shape of protein, which contains repeating secondary structure
Quaternary structure- Molecule composed of two or more separate proteins