Organic Macromolecules##/
Inorganic molecules play an important role in the metabolism of living organisms. But without water, they account for only about 1.5% of their mass. inorganic molecule.
Functional Groups
As we have seen, organic molecules contain carbon and hydrogen atoms. And each carbon atom can form four covalent bonds with other atoms.
Atoms of other elements bond. These carbon skeletons form an unlimited number of connections. Other elements such iron, copper, molybdenum, manganese, and zinc.
And iodine is important in some proteins. Atoms are often grouped in specific arrangements called functional groups. For example, -NH is found in all amino acids.
These molecules are called macromolecules because they are so large. Are lipids, carbohydrates, proteins, and nucleic acids.
Lipids
Lipids are a diverse group of organic macromolecules. That is not composed of regular subunits. They have one common property of being hydrophobic.
In other words, organisms make lipids through dehydration synthesis reactions. That form esters between three chain fatty acids and an alcohol called glycerol.
Fats
The three fatty acids in a fat molecule. Which can be the same or different, usually having 12 to 20 carbon atoms in each Saturated fat. Such as those found in animals. Are usually solid at room temperature because of their fatty acids. Are based on p.1. 75 compares the structures and melting points of four common fatty acids.
Fats contain abundant energy stored in covalent carbon-carbon bonds fact. An important role of fat in living organisms is energy storage.
Phospholipids are like fats. But contain only two fatty acid chains instead of three. In phospholipids, the 3rd carbon atom of glycerol is i. The fatty acid "tail" of the phospholipid molecule is non-polar.
And so hydrophobic, whereas the phospholipid "head" is polar and so hydrophilic. 4 As a result, Phospholipid.
Id placed in an aqueous environment always self-assembles into a shape. That keeps the fatty acid tails away from water. One way to do this is. Hydrophobic fatty acid tails accumulate. In the anhydrous interior of the bilayer. The polar phosphate head points towards the water because it is hydrophilic.
Phospholipid
Phospholipid bilayers make up the membranes surrounding cells. And the inner membranes of plant, fungal, and animal cells. Waxes are composed of long-chain fatty acids. Bonded to long-chain alcohols via ester bonds.
Waxes do not have hydrophilic heads. So, they are also insoluble in water. Microorganisms such as Mycobacterium tuberculosis.
Steroids
The final group of lipids is steroids. Steroids are composed of four rings attached. and have a variety of side chains and functional groups. Steroids play many roles in human metabolism. Some act as hormones. Others are steroids.
Similar sterol molecules in their membranes, sterols, are OH-functional steroids. That disrupts the dense packing of fatty acid chains in phospholipids.
This keeps the fluidity and temperature of the membrane low. Without cholesterol-like steroids, cell membranes become rigid and inflexible when cold.
Carbohydrates, proteins, and nucleic acid molecules. Are made up of simple subunits called building block monomers 15.
The monomers of these molecules are linked together as polymers16. Some macromolecular polymers are made up of hundreds of monomers.
Carbohydrates
Carbohydrates are organic molecules composed only of carbon, hydrogen, and oxygen atoms. Most carbohydrate compounds contain equal amounts of oxygen and carbon atoms.
Since there are twice as many hydrogen atoms as carbon molecules. The general formula for carbohydrates is where n is the number of CH, and O units.
Carbohydrates play many important roles in the body's large carbohydrates. As starch and glycogen are used for long-term storage of chemical energy. And most cells use small carbohydrate molecules as a ready energy source.
N.A. and R.N. A. The latter also contains carbohydrates. Which are converted to amino acids. Carbohydrate polymers form the cell walls of most fungi, plants, algae, and prokaryotes.
And are involved in intracellular interactions between animal cells. For example, special carbohydrates on the surface of white blood cells.
Monosaccharides
The simplest carbohydrates are monosaccharides. Seven monosaccharides. Monosaccharide class names are formed from a prefix indicating. The number of carbon molecules and a suffix for its position.
Molecules and Hexose are six-carbon molecular sugars. Pentose and hexose are particularly important in cellular metabolism example deoxyribose.
Pentose is the sugar component of DNA. Glucose is a hexose, the primary energy molecule in cells. And fructose is a hexose found in fruits. Chemists assign numbers to carbon atoms.
Monosaccharides can exist as linear molecules. But due to their energetic dynamics. They usually adopt a cyclic. There may be many ring structures.
For example, glucose can have either the alpha or beta configuration. These configurations are different, as explained later. It plays an important role in the formation of polymers.
Disaccharide
A disaccharide is formed when two monosaccharide molecules are combined by dehydration synthesis. For example, two hexoses, glucose. And fructose form sucrose a compound of glucose and fructose.
And water molecules. Other disaccharides are maltose and lactose disaccharides can be broken down. Their constituent monosaccharides by hydrolysis.
Polysaccharides
Polysaccharides D.N. E.D.N. C.R. Yet. Only the glucose monomers differ in polysaccharides. As the composition of the monosaccharide monomers. And their shape can differ.
Cellulose is the main component of the cell walls of plants and some green algae. Is a long unbranched molecule. With only the b-monomer of glucose attached to each monomer between the 1st and 4th carbons.
Is the starch store, contains only 1,4 bonds, and is unbranched. Glycogen is a branched molecule with both A,4 and A,6 linkages. Bacterial cell walls are made of peptidoglycan.
Which is composed of polysaccharides and amino acids. Polysaccharides combine with lipids to form glycolipids. Which form cell markers for the human blood group system.
Proteins
The most complex organic compounds are proteins. Which are composed of carbon, hydrogen, oxygen, nitrogen, and sulfur.
Proteins serve many functions in the cell, including structure. Proteins are structural components found. In cell walls, membranes, and the cell itself.
Proteins are also the major structural materials of hair and nails. Epidermal cells, muscles, flagella, and cilia. Enzyme Catalysts Catalysts are chemicals. That increase the speed or likelihood of chemical reactions.
Protein catalysts in cells are called enzyme regulation. Some proteins regulate cellular function. By inducing or inhibiting the action of other proteins. Hormones are examples of regulatory proteins.
Some proteins act as channels and pumps. That move substances in and out of cells. Defense and attack Antibodies and complements are examples of proteins.
That protects the body from pathogens. Some bacteria also produce these types of proteins that destroy bacteria. The function of a protein depends on its shape.
Amino Acids
Which is determined by the molecular structure of its building blocks amino acids. Proteins are polymers made up of monomers called amino acids.
Amino acids contain one hydrogen atom. One basic amino group, and one acidic carboxyl group. Al is attached to a carbon atom called the 4th bond.
And the carbon has a different side group for each amino acid. It can be side groups, hydrogen atoms, or various chains. Hundreds of amino acids are formed.
But most organisms cannot synthesize proteins. Only 21 kinds of amino acids are used. Amino acids affect not only how proteins interact with other molecules. But also how they interact with each other.
Changes in the side groups of amino acids can affect the normal function of proteins. It can be damaged. Amino acids contain both an acidic carboxyl group and a basic amino group. So they are both charged and soluble in water.
Aqueous solutions of organic molecules such as amino acids. And simple sugars pass through the solution. Light rays bend. The molecule is known as D-type '9.
Other molecules rotate in the opposite direction of light and are known as L-forms. Many organic molecules exist in both D and L forms. Which are stereoisomers of each other, they contain the same atoms.
Although and are functional groups, they are mirrors of each other. We cannot talk about the amino acid glycine present in proteins. The organism is almost without exception. In metabolism uses D-sugars and polysaccharides.
Rare stereoisomers of amino acids and I-sugars are also present. In some bacterial cell walls and some antibiotics.
Peptide Bond
Peptide-binding Cells bind amino acids in chains that resemble beads in a rosary. Dehydration synthesis forms a covalent bond. The carbon of the carboxyl group of the amino acid.
And the nitrogen of the amino group of the amino acid present in the chain. Cells add amino acids according to the animal's genetic instructions.
Scientists have given the covalent bond between amino acids. A special name is the peptide-2 bond. A molecule composed of two amino acids linked by a peptide bond is called a dipeptide.
Protein Structure
Proteins are unbranched polypeptides made up of hundreds to thousands of amino acids. Joined in specific patterns determined by genes.
Understanding protein structure is important for certain types of chemical reactions. Because the structure of a protein molecule is related to function.
Important for antibiotic efficacy and specific protection against microorganisms proteins. At least three levels of structure and some proteins have four.
Morphology Primary Structure The primary structure of a protein. Is the sequence of amino acids. Different types of amino acids are used by the cell for proteins.
Although not all types are present in all proteins. The primary structure of a protein is the length and order of its amino acids. It's different.
Changing a single amino acid can have a large impact on the structure and function of a protein. But this is not always the case. For example, a single amino acid substitution.
At position 136 of a specific sheep brain protein can result in a cellular prion mutant protein. That causes a disease called scrapie. The mutated protein is passed on to cows to cause mad cow disease.
And is passed from cows to humans to be inherited. Ionic bonds, hydrogen bonds, and hydrophobic and hydrophilic properties. Cause many polypeptide chains fold into turns or atria called b-sheets.
Proteins are made up of both these tangles and sheets bound. By short amino acid sequences to form such secondary structures. No structure is displayed.
Proteins are formed by their primary structure. The Creutzfeld-Jakob sheets of various types of organisms. Have anti-helices where normal proteins would be.
Tertiary structural polypeptides that are not repeated like helices. Into complex three-dimensional shapes designed to carry out protein functions.
Scientists begin to understand the interactions that determine the tertiary structure. It is clear that hydrogen bonding, and ionic bonding.
And other molecular interactions in amino acids are important. For example, the nonpolar sidebands of molecules. On the opposite side, the presence of water rotates inwards.
Some proteins form strong covalent bonds between the sulfur atoms. Bringing them near causing the folding of the polypeptide. These disulfide bonds are important for maintaining.
The tertiary structure of many proteins. Quaternary Structure Some proteins are composed of two or more polypeptide chains linked. By disulfide bridges or other bonds. The shape of such proteins can be globular or fibrous.
Organisms can post-modify proteins by conjugating them with other organic or inorganic molecules. Examples include glycoproteins or glycoproteins.
That bind carbohydrates, lipoproteins that bind lipids, and metal ions. And nucleoproteins that bind nucleic acids are bound.
Since the shape of a protein determines its function, anything. That disturbs the shape and will interfere with its function.
As we have seen, amino acid substitutions can alter form and function. It can break ionic bonds. This can lead to the destruction of the three-dimensional structure. This process is called denaturation. Swelling may be temporary.
Nucleic Acids
The nucleic acids deoxyribonucleic acid and ribonucleic acid. Are important as the genetic material of cells and viruses. N.N.A. also functions as an enzyme that produces polypeptides.
N. Both A. and R.N.A. are branched macromolecular polymers. That differs in the structure of the units, which will be discussed later.
Nucleotides and Nucleosides
Each nucleic acid monomer, used as a nucleotide, is composed of three parts. A pentose sugar, either deoxyribose or ribose five cyclic nitrogenous bases.
Adenine (A), guanine (G), cytosine (C), thymine (T), or uracil. Adenine and guanine form a group. There are two ring molecules called purines. And cytosine, thymine, and uracil have a single ring called pyridine.
DNA contains A, G, C, and T bases, and RNA contains A, G, C, and U. Chair. As the name suggests, the D.N.A. nucleotide deoxyribose and the R.N.A. named nucleotide.
Are nucleotides that lack an OH site? That is, a nucleoside has only one nitrogenous base attached to the sugar. Each nucleotide or nucleoside is also named after its base.
Thus, nucleotides are composed of ribose and uracil. And phosphate is the nucleotide of uracil RNA. Also known as uracil ribonucleotides, a nucleoside composed of adenine. And deoxyribose is adenine DNA nucleoside.
Nucleic Acid Structure
Nucleic acids, like polysaccharides and proteins, are polymers. These nucleotides are joined. By a covalent bond between the phosphate of one nucleotide.
And the sugar of another. Polymerization results in the formation of a linear backbone of branched sugars. And phosphates, extending from the base.
Like the teeth of a comb, the ends of the nucleotide strands are different. At one end, called the 5-end the fifth carbon of the sugar is attached to the phosphate group.
Carbon 3 on the other end is not yet attached to the phosphate group. The base atoms of a nucleotide are arranged. So that hydrogen bonds. Can form between specific bases of two adjacent nucleic acid strands.
Three hydrogen bonds form a bond pair consisting of cytosine (C) and guanine (G). Two hydrogen bonds occur between adenine (A) and thymine (T) in DNA. Hydrogen bonds are not formed between other combinations of nucleotide bases.
For example, adenine does not pair with cytosine, guanine, or other adenine nucleotides. In cells and most viruses, they use DNA as their genome.
The DNA molecule is double-stranded. That's what I specialize in. Nucleotide base pairing makes the opposite strand composed of complementary nucleotides.
For example, if the A chain has an ARG sequence, its complement is TACGA. The two strands are also parallel. That is, running in the opposite direction.
One strand runs from the 3' end to the S' end. Its complementary part runs in opposite directions from the 5' end to the 3' end.
Although hydrogen bonds are weak bonds, thousands of hydrogen bonds. Exist at room temperature to form a stable two-sided DNA molecule.
Form a molecule that looks like a ladder. Hydrogen bonding also causes the phosphate-deoxyribose backbone. To fold into a helix.
A typical DNA is thus a double helix. Parvovirus uses single-stranded DNA, which is an exception to this rule.
Functions of Nucleic Acids
DNA is the genetic material of all organisms and many viruses. Provides instructions for the synthesis of RNA molecules and proteins.
Controlling the synthesis of enzymes and regulatory proteins. DNA A controls the synthesis of all other molecules present in the organism.
Genetic instructions are given in the sequence of nucleotides. That makes up nucleic acids. DNA has only four types of bases yet they are arranged in specific patterns.
That creates genetic diversity and encodes an infinite number of proteins. Much like the four-letter alphabet. can. Spell out a lot of words.
They copy DNA molecules and pass the copies on to their progeny, ensuring that each cell carries them. The instructions it needs to survive.
Several ribonucleic acid messengers such as R.N.A. A. and ribosomal R.N.A. play a role. In catalyzing protein synthesis. RNA molecules also appear in the form of genomes instead of DNA. RNA virus.
ATP Phosphate is a reactive functional group in nucleotides. And other molecules that can form covalent bonds. With other phosphate groups to form phosphate and triphosphate molecules.
Ribose is one such molecule composed of nucleotides. The names of these molecules or show. The number of nucleotide bases and their phosphate groups. That is important for many metabolic reactions.
Cells generate adenosine monophosphate from the nitrogenous base adenine, a nib sugar. And a phosphate group. Adenosine diphosphate with two phosphate groups. Adenosine triphosphate or ATP with three phosphate groups.
ATP is the primary source of short-term, recyclable cellular energy supply. A large amount of energy is released when the phosphate bond of ATP is broken. More energy is released from the phosphate bond.
Then is available from other covalent bonds. For this reason, the phosphate-phosphate bond of ATP. Is known as a high-energy bond. And can be viewed as the symbol for A.O.P. Energy released. In the form of AMP when ATP is converted to ADP and the phosphate is removed from AMP.
