Biochemistry Flashcards
Name the functional groups
Hydroxyl, carbonyl, carboxyl, amino, methyl, phosphate, sulfhydral
Name the functional groups associated with carbohydrates
Hydroxyl, carbonyl
Name the functional groups associated with proteins
Hydroxyl, carbonyl, amino, sulfhydryl
Name the functional groups associated with nucleic acids
Hydroxyl, carbonyl, amino, phosphate
Name the functional groups associated with lipids
Hydroxyl, carboxyl, phosphate
What is a macromolecule
Large, complex molecules usually composed of repeating units of smaller molecules covalently linked together
What is a monomer
One sub unit
What is a polymer
Several sub units (monomers) combined
What is a carbohydrate
A biological macromolecule that contains carbon, hydrogen and oxygen in a 1:2:1 ratio
Provide short or long term energy storage
What is a monosaccharide
A carbohydrate composed of between 3 and 7 carbon atoms
“Mono” means one, “saccharide” means sugar
Considered to be simple sugars such as glucose, fructose and galactose
Glucose, fructose and galactose are isomers
What is an isomer
One of two or more molecules with the same number and type of atoms, but different structural arrangements
What are the two equilibrium that sugars exist in
Cyclic (Haworth model) and acyclic (fisher projection)
What is a disaccharide
A carbohydrate composed of two monosaccharides joined by a glycosidic linkage
An example is sucrose, composed of glucose and fructose
What is a polysaccharide
A carbohydrate polymer composed of many monosaccharides joined together by covalent bonds
Explain starch
Responsible for energy storage in plants
Long chain of glucose subunits
Provide short term energy storage
Explain glycogen
Responsible for energy storage in animals
Animals and humans when consuming glucose break it down and convert it into glycogen where it is stored in the liver
Has a larger amount of branching than starch in order to pack more glucose units into a single cell
Too much glycogen can result in glycogen storage disease which is usually hereditary
Explain cellulose
Used by plants to build walls
Structural molecule as it protects and supports the plant
Only a few bacterial species produce the digestive chemicals to break it down, mammals and humans do not have the bacteria
Explain lipids
Lipids are hydrophobic
The presence of many energy rich C-H bonds makes lipids efficient energy storage molecules
Lipids provide long term energy storage, provide insulation, protects and cushion the organs
What are the four classes of lipids
Triglycerides, phospholipids, steroids, waxes
Explain triglycerides
Triglycerides are a lipid molecule composed of a glycerol molecule and three fatty acids linked by ester bonds
What is a fatty acid
A fatty acid is a hydrocarbon chain ending in a carboxyl group
What are unsaturated fatty acids
Fatty acids with double bonds
0 double bonds= saturated
1 double bond= monounsaturated
2+ double bonds= polyunsaturated
Explain saturated fats
No double bonds between carbon atoms
Fairly straight, pack tightly
Solid at room temperature
Explain unsaturated/polyunsaturated fats
One or more double bonds between carbon atoms
Cis double bonds cause kinks in molecules
Cannot pack tightly, trans double bonds don’t allow bending
Explain hydrogenation
Add hydrogen atoms to double bonds
For example, adding hydrogen atoms in vegetable oils to convert them to semi-solids like margarine
Explain trans fat
Trans fats are unsaturated fatty acids that are not commonly found in nature. The common unsaturated acids have a cis configuration of H’s attached to double bonds. Trans fatty acids have a trans configurations of H’s attached to double bonds
Cis- H’s go the same way
Trans- H’s go the opposite way
What are phospholipids
Lipids composed of a glycerol molecule bonded to 2 fatty acids and a phosphate groups with an R group
The head of the phospholipid molecule is polar, thus the head is hydrophilic while the tail is non-polar and hydrophobic
What is a phospholipid bilayer
A structure with hydrophilic heads of phospholipids directed towards the aqueous environment and hydrophobic tails directed toward the centre, interacting with each other
This keeps water out, allows the cell to be selective of what goes in and out
What is a micelle
A single layered barrier formed when phospholipids are added to water
Forms spheres, forms a single layer membrane with a hydrophobic interior
What are steroids
Lipids composed of four attached based rings
Explain cholesterol
A key component of cell membranes
High cholesterol can restrict blood flow. Cells convert cholesterol into compounds such as vitamin D and bile salts. Important for keeping cell membrane fluid, not rigid
Explain high density lipoprotein (HDL)
Aids in moving cholesterol through blood stream
Removes cholesterol by transporting to liver
Explain low density lipoprotein (LDL)
Deposits cholesterol onto vessel wall
Causes blockages
What are waxes
Lipids containing long chain fatty acids linked to alcohols or carbon rings
Hydrophobic, firm, pliable consistency, used as waterproof coating on plants and animals
What functions do proteins perform
Catalyze chemical reactions, provide structural support, transport substances in the body, enable organisms to move, regulate cellular processes, provide defence from disease
What is an amino acid
An amino acid is an organic molecule composed of a central carbon atom bonded to a hydrogen atom, an amino group, a carboxyl group and a R group
Explain the primary structure of a protein
The primary structure of a protein is the polypeptide chain formed by covalent peptide bonds
Explain the secondary structure of a protein
The polypeptide chain begins to fold and interact with itself due to hydrogen bonding. It has been observed to form two possible orientations: an alpha helix and a beta pleated sheet
Explain the tertiary structure of a protein
This structure forms due to hydrophobic and hydrophilic interruptions within the cellular environment. Alpha helixes and beta sheets will fold and re-orient themselves so that:
Hydrophilic groups will direct towards the water
Hydrophobic groups will be directed towards the interior of the folded protein, to avoid interaction with water
Explain the quaternary structure of a protein
When the different tertiary structure group together and interact they form a large quaternary structure.This is the functional protein stage
Explain denaturation
Understood and conditions, proteins will unfold to do breaking of bonding interactions with R groups. For example changes in temperature, change in pH of the environment, exposure to harmful chemicals, high salt concentrations)
Protein can no longer function normally at this point
Explain nucleic acids
Biological macromolecule composed of nucleotide monomers. The two types are DNA and RNA
DNA is composed of nucleotides containing sugar deoxyribose
RNA is composed of nucleotides containing the sugar ribose
Explain DNA
Composed of four different types of nitrogenous bases: adenine, thymine, guanine and cytosine
Stores genetic information of an organism
H in DNA
Explain RNA
In RNA uracil is used in place of thymine
Participates in protein synthesis
OH in RNA
What is a nucleic acid composed of
A phosphate group, a sugar, a nitrogenous base
What is the monomer of a carbohydrate
Monosaccharide
What is the polymer of a carbohydrate
Polysaccharide
What are the bonds between the monomers of a carbohydrate
Glycosidic linkage
What is the monomer of a lipid
Glycerol and 3 fatty acid chains
What is the polymer of a lipid
Triglyceride
What are the bonds between the monomers of a lipid
Ester bonds
What is the monomer of a protein
Amino acids
What is the polymer of a protein
Polypeptides
What are the bonds between the monomers of a proteins
Peptide bonds
What is the monomer of a nucleic acid
Nucleotides
What is the polymer of a nucleic acid
Strands