Unit 6: General Biochemistry

Carbon can form 4 stable covalent bonds with many different types of atoms Creating stable/complex structures and molecules. Covalent bond: a bond created by the sharing of electrons between two atoms

A reaction that removes water to form a bond between two molecules and requires energy. Condensation reactions: remove water to form a bond between two molecules - Requires energy - If it is a bond between two monosaccharides (simple sugars) it is a glycosidic bond

Two monosaccharides bonded together, such as maltose.

Many monosaccharides bonded together, for example, amylopectin.

1-4 linkages → linear (n1 car – n4 carbon) (e.g. maltose) 1-6 linkages → branched (amylopectin)

Alpha glucose and Beta glucose.

The chemical breakdown of larger molecules into small molecules, typically by hydrolysis. Hydrolysis: Adding water to break the bonds of polymers

Monosaccharide: simple sugar - Triose : 3 carbon sugars - Pentose : 5 carbon sugars : ribose, deoxyribose - Hexose: 6 carbon sugars 5C and 6C forms ring with an oxygen atom

Most important monosaccharide → Glucose: C6H12O6 - Soluble in water (polar) - Small - Stable - Produces energy when oxidized (cell respiration)

Polysaccharides: Many monosaccharides bonded together They are all: - Not soluble (implications in transportation, osmolarity) - No fixed size But might have different in functions: - Structural support → Cellulose in cell walls of the plants - Energy storage → Glycogen (in animals) and starch (in plants)

Cellulose: Structural component in plants’ cell walls - B-glucose with **1-4 **glycosidic bonds, linear Explanation: Since glucose molecules are polar they have partially negative and positive poles and when they are parallel to each other they can form hydrogen bonds that hold the chains together So it is very strong → it’s a structural component

Glycoprotein: Polypeptide with attached carbohydrate chain - On the cell membrane with chains facing outwards - Outside of the cell, the carbohydrate chain is used for the cell-to-cell recognition - Cells approach and then glycoproteins recognizes

All lipids are hydrophobic - Non-polar, non-soluble in water Types: Fats, oils, waxes and steroids

Fatty acid Carbon chains, with hydrogens attached to them. Methyl group (CH3) - Carbon chain – Carboxyl group (COOH) We can make a triglyceride or phospholipids through condensation reactions - Triglyceride: glycerol + 3 fatty acid chains - Phospholipid: glycerol + 2 fatty acids + phosphate group

Fatty acid types: aren’t identical, can come in several different forms - Saturated - Monounsaturated - Polyunsaturated Saturated fatty acids - Have single bonds - Straight - Are solid at room temperature - E.g. butter and margarine Monounsaturated fatty acids - Contain one double bond (bending the chain) - Are liquid at room temperature. Polyunsaturated fatty acids - Contain more than one double bond between 2 carbons (multiple bendings) Has two types - Cis-unsaturated fatty acids - Trans-unsaturated fatty acids

Adipose tissue - Stores energy as **triglycerides **under the skin and around organs - Provides thermal insulation, not good heat conductors, so they help keep organisms warm - Are good shock absorbers (protection) Triglycerides are great for storing energy long-term - Stable - Insoluble → do not affect osmolarity - Energy-dense (9cal/g compared to carbs 4 cal/g)

When you place phospholipids in watery solutions they arrange in a bilayer - Tails pointing inwards (away from water) - Heads pointing outward (towards the water) Role: - Helps compartmentalize the cells - They determine the permeability, polar molecules like glucose can’t pass from the hydrophobic tails Steroids are non-polar lipids so they can pass through Ex: testosterone, 3 six-sided rings, and one five-sided ring

• Amino acids are the building blocks of proteins • 20 different types of amino acids NH2 amine group - central carbon - COOH carboxyl group - hydrogen and R group R group changes but the rest is identical for the rest

Dipeptide: 2 amino acids Polypeptide: many amino acids **Condensation reactions: **remove water to form a peptide bond between amino acids

20 different amino acids Plants can produce all 20 amino acids. Humans can only make** 9 **of them so we need to consume 11 of it in our diet Many animal proteins do have all of the essential amino acids but if you have a vegan or plant-based diet we need to eat the variety of foods to make sure that we get all types of amino acids.

Changes in pH and temperature can lead to denaturation, a permanent change in protein structure and function. A protein’s function is very specific to its shape

Catalysts that increase the rate of chemical reactions Are not consumed, can be reused Are protein-based. Metabolism: all of the enzyme-catalysed reactions in a cell Enzymes are substrate-specific (each substrate in each reaction needs its own enzyme) Lots of different enzymes

• Anabolic: small → bigger, forming bonds, requires energy (e.g., photosynthesis) • Catabolic: big → smaller, breaking bonds, releases energy (e.g., cell respiration, hydrolysis)

The active site of an enzyme changes shape for substrate binding, facilitating the reaction. After product is released, the active site returns to its original shape