SBI4U - BioChem

Lipids

• Are built from glycerol and fatty acid chains, not true polymers
• Includes triglycerides with a glycerol group and are molecules with fatty acid chains
• Phospholipids have a glycerol group, fatty acid tails, and a phosphate group
• Steroids have a structure of four rings
• Waxes contain long chains

Nucleic Acids

• Nucleotides are the monomers
• RNA stands for Ribonucleic Acid
  • Contains an extra oxygen
  • Exists as a single helix
  • Has Uracil rather than Thymine
• DNA stands for Deoxyribonucleic Acid
  • Lacks one oxygen
  • Forms a double helix

Base Pairs

• Guanine (G) pairs with Cytosine (C)
• Adenine (A) pairs with Thymine (T) in DNA
• Adenine (A) pairs with Uracil (U) in RNA

Macromolecules

• Functional groups are the reactive parts of organic molecules and typically make the molecule polar

Groups and Types of Molecules

• Carbohydrates include monosaccharides, disaccharides, and polysaccharides
• Proteins include amino acids
• Lipids include fatty acids, glycerol, steroids, and waxes
• Nucleic acids include nucleotides

Carbohydrates

• Monomers are small, single units, while polymers are larger and made of multiple units
• Alpha glucose has hydrogen above carbon 1
• Beta glucose has hydrogen below carbon 1
• Monosaccharides are single units includes glucose, fructose, and galactose
• Disaccharides are two monosaccharides linked, such as maltose, sucrose, and lactose
• Polysaccharides are many or multiple monosaccharides linked, like starch, glycogen, and cellulose
• Glycosidic bonds form when two monomers bond, involving a condensation/dehydration reaction where water is removed, or hydrolysis when water is added to break bonds

Proteins

• Amino acids are building blocks, approximately 20 kinds
• Polymers are made up of amino acid monomers
• Amine and carboxyl groups determine the kind of acid
• Peptide bonds form between amino acids via a condensation reaction

Stages of Protein Formation

• Primary sequence refers to the sequence of amino acids
• Secondary stage involves coiling and folding into alpha helices or beta sheets
• Tertiary formation further coils into a specific shape
• Quaternary structure involves multiple polypeptides interacting

Polypeptides

• The building process involves making larger proteins
• Two amino acids form a dipeptide.
• Three amino acids form a polypeptide
• The breaking process occurs in hydrolysis reactions, releasing water

Protein Structure Levels

• Primary structure details the sequence of amino acids to form a polypeptide
• Secondary structure shows the polypeptide coiling into alpha helices or looping into beta sheets
• Tertiary structure involves further coiling into a specific shape
• Quaternary structure shows multiple polypeptides interacting

Carbohydrates

• The formula is (CH2O)n with a 1:2:1 ratio of carbon, hydrogen, and oxygen
• Number of carbon atoms includes pentose sugars or hexose sugars
• Every carbon is attached to an oxygen
  • Only one carbon is double-bonded to an oxygen (carbonyl)
  • Other carbons exist bounded to an alcohol
• They are polar and soluble in water

Pentose Sugars

• These molecules need to get study
• Triglycerides, Waxes, Phospholipids, and Steroids

Organic Compounds

• Include carbohydrates, lipids, proteins, and nucleic acids

Macromolecules

• Large molecules made of repeating units
  • Monomers are single units
  • Polymers are large units made by bonded monomers

Functional Groups

• These include hydroxyl, carbonyl, phosphate, amino and lipids
• Carbohydrates, proteins, and DNA/ATP
• Condensation reaction which leads t glycolidic bonds

Carbohydrates

• Each carbon can form four bonds
• Occur in five major groups: sugars, monosaccharides, disaccharides, and polysaccharides
• They function by providing energy and as storage or structural components, such as starch in plants, glycogen in animals, and cellulose in cell walls

Monosaccharides Link

• Two of these molecules can form maltose, sucrose, and lactose

Types of Saccharides

• Pentose saccharides have the formula (CH2O)5
• Hexose saccharides have the formula (CH2O)6
• Alpha glucose has hydrogen above a point
• Beta glucose has hydrogen below a point

Molecules in the Body

• Proteins are in the body

Protein Characteristics

• Contains carbon, hydrogen, oxygen, nitrogen and sometimes sulfur or phosphorus
• Are the result of long chains of amino acids

Amino acids

• R groups (radicals) are what makes each different
• Have different properties depending on the R group
• 20 amino acids are needed by humans
• Nine are essential and must come from diet

Bonding Sites

• Carboxyl groups bond with the amino group of another amino acid
• Dehydration/condensation reactions can release water
• Peptide bonds from as a result

Lipids composition

• Includes fats, phospholipids, steroids, and waxes
• They function in storage, promotion or insulation within animals

Energy Content

• Lipids yield more energy than carbs
• In particular fat is a blubber in animals

Cell Membranes

• Contain phospholipids, that are composed, of glycerol, fatty acid, fat,

Triglycerides

• The molecules are composed of one glycerol and three fatty acids
• These can synthesize through condensation reactions
• Ester linkages form as a result

Phospholipids

• Serve as the structural component in cell membranes
• Contains 1 glycerol module, 2 fatty acid , and a phosphate group

Phospholipids

• Phosphate groups are hydrophilic and polar
• Fatty acid tails are hydrophobic and nonpolar

Steroids

• Includes signaling molecules
• Contains four fused hydrocarbon rings and several different functional groups

Waxes

• Long chain fatty acids
• Exhibit the structure C-H--C30-32H61-66

Nucleic Acids

• There are two main types
• DNA (deoxyribonucleic acid)
• RNA (ribonucleic acid)
• It has a genetic role and function

Genetic Material

• It contains genes
• It is often hereditary
• Exists as a nucleotide monomer

DNA

• Each nucleotide has a sugar
• Deoxyribose and ribose
• Nitrogenose base that vary in types
• Each consists of phosphate group

Nucleotide Composition

• DNA contains deoxyribose with a missing oxygen
• RNA consists of ribose and does not miss an oxygen atom

Nitrogenous Bases

• Two Purines contain 2 rings
• Adenine (DNA, RNA)
• Guanine (DNA, RNA)
• Pyrimidines each contain 1 ring
• Cytosine (DNA, RNA)
• Thymine (DNA) which is exclusive to only DNA
• Uracil (RNA)

DNA Building Blocks

• Each phosphate group is linked together with phosphoric acid
• Also contains a phosphate ion
• Includes G-C and A-T combinations
• Always contain the molecules
• Adenine,
• Thymine ,
• Cytosine
• Uracil

Cell Membranes

• Cell or plasma membranes control what enters and exits cells
• Cells need food to enter and waste to exit, and membranes facilitate communication

Cell Membrane Structure

• Composed of a phospholipid bilayer with two layers
  • The hydrophilic head attracts water and is soluble in water
  • Hydrophobic tails repel water and are insoluble in water

Phospholipids

• There is another term Hydrophilic.

Cell Structure

• Phospholipids face towards the outside and inside of the cell

Substances

• Only hydrophilic heads are in contact
• Substances block other passages

Membrane Fluidity

• Saturated fatty acid tails pack together more densely at colder temperatures
• Unsaturated fatty acid tails cannot pack together, forming kinks from double bonds
• Cell membranes contain a good level of fluidity at nominal temperatures

Cell Membrane Function

• Contains integral and peripheral membrane proteins
• Phospholipids form a bilayer providing a semi-permeable barrier
• Cholesterol maintains membrane fluidity and stability
• Integral proteins transport molecules or act as receptors or enzymes, spanning through the phospholipid bilayer
• Peripheral proteins provide structural support and attach to surfaces
• Carbohydrates aid in cell recognition, signaling, and adhesion

Main Functions of Proteins

• Transports key molecules
• Attaches and recognizes components for the cytoskeleton
• Receptors for signaling
• Enzymes for biochemical reactions

Location in Membrane

• Components in the main structure
• Emdedded within, with integral membrane
• Used attached and signaled