Macromolecules: Condensation and Hydrolysis Reactions

Macromolecules

• Polymers consist of multiple structural units linked by covalent links and being identical or similar.
• Monomers are structural units, polymers are akin to trains, monomers are akin to wagons.
• Synthesis reactions require energy and form a water molecule, also called dehydration or condensation reactions.
• Degradation reaction releases energy while requiring water, also called hydrolysis.
• Macromolecules have great diversity due to multiple ways of arranging monomers.
• Twenty-six alphabet letters enables a multitude of words, while ten digits allow infinite numbers.
• Carbohydrates, proteins, nucleic acids, and lipids are examples of macromolecules.

Condensation and Hydrolysis Reactions

• Dehydration reactions synthesize polymers, such as protein synthesis, requiring energy by losing a water molecule to form a new bond.
• Hydrolysis reactions degrade polymers, such as digestion, releasing energy by adding a water molecule and breaking the bond between monomers.

Carbohydrates

• Carbohydrates consist of C, H, and O.
• Carbohydrates functions include immediate and short-term energy, genetic material support that form the backbone in DNA, and structure.
• Monosaccharides are simple sugars with multiples of CH2O formula, but glucose, fructose, galactose, and ribose exist as other options.

Disaccharides and Polysaccharides

• Disaccharides require the consumption of energy.
• Polysaccharides are complex sugars with 3+ monosaccharides linked by covalent/glycosidic bonds and often contain hundreds/thousands of glucose units.
• Polysaccharides function as energy storage in the form of starch in plants, stored in tubers and hydrolyzes as needed.
• Glycogen in animals stored in the liver and muscle cells and depletes within a day in humans.

Structural Polysaccharides

• Cellulose forms plant cell walls.
• Plants produce around 100 billion tons of cellulose annually: the most abundant organic compound on Earth.
• Cellulose forms insoluble fibers that are indigestible for animals.

Proteins

• Proteins make up 50% of a cell's dry mass with about 100,000 different proteins in the body.
• Proteins are polymers of amino acids using 20 different amino acids.
• Proteins consist of an amine group, variable radical, and carboxyl group.
• Covalent bonds between the carboxyl and amine groups are peptide bonds for the structure.
• Proteins consist of one or more polypeptides having a particular 3D shape linked together by covalent bonds.

Protein Organization

• The sequence dictates primary structure and other levels of structure.
• Secondary structure involves hydrogen (H) bonds that fold the polypeptide into helices α and sheets β, involving only atoms of the polypeptide chain.
• Tertiary structure is the "true protein" due to interactions between lateral chains and determines function dependent on the 3D form.
• Quaternary structure involves the 3D arrangement of multiple tertiary structures, though not necessary for all proteins.

Protein Functions

• Enzyme catalysts accelerate reaction rates.
• Proteins are resources that are reusable because they can be secreted for hormone coordination.
• Proteins can be used for the movement of cells.
• Immune functions are enabled through protein interactions.
• 5. Proteins catalyze specific substrate reactions for each enzyme from the active site consisting of an amino acid sequence where the substrate joints.

Enzyme Catalytic Cycle

• Substrates enter the enzyme's active site
• The enzyme changes shape.
• Substrates are held by hydrogen and ionic bonds.
• The active site lowers activation energy with the reaction accelerating to over one thousand cycles a second for synthesis, degradation, and substitution reactions.

Nucleic acids

• Nucleic acids are polymers of nucleotides separated into ADN vs ARN.
• ADN is a deoxyribonucleic acid responsible for storing information genetics, the genes sequence code for proteins.
• ARN is a ribonucleic acid derived from ADN intended as the intermediate for ADN synthesis.
• Nucleotides include a monosaccharide, a phosphate group with an extremes, a base azotée.

ADN vs ARN

• ADN has a double helix, antiparallel and complementary strands.
• Knowing the sequence of one strand allows deducing the sequence of the other.
• ADN forms A–T and G–C base pairs with hydrogen bonds between strands, elucidated by James Watson and Francis Crick.
• ARN follows A-U and C-G complementary pairs.

Lipids

• Lipids are diverse structures that are non-polymeric and mainly consist of C and H, containing few polar bonds making lipids insoluble in water.
• Fats - Triglycerides consist of 1 glycerol and 3 fatty acids, providing twice the energy per gram than carbohydrates.
• Phospholipids, consists of with a phosphate group that's hydrophilic and with a glycerol backbone, function as thermal insulation.
• Steroids are are composed of four carbon rings, some can be cholesterol for animal membrane stability while others can be hormones.

Polarity and hydrogen Bonding

• More electronegative atoms create covalent bonds that lead to partial negative and positive charges, allowing molecules to be bonded to adjacent molecules by hydrogen bonds.
• Cohesion is important because it forms a lattice effect preventing non polar molecules from dissolving, polar molecules will dissolve due to the hydrogen bonds.