Study Unit 2 (II) Flashcards
What is a protein?
A protein is a polypeptide chain with more than 50 amino acids
What are conjugated proteins?
Proteins that contain prosthetic groups
What are the purpose of prosthetic groups like organic and non-organic components?
They determine the catalytic activity of proteins
Example of a conjugated proteins
Haemoglobin
Primary structure of proteins
Specific sequence of amino acids as specified by the gene, held together by covalent/peptide bonds
Secondary structure of proteins
Portions of the structure begin to fold in unique 3D formations due to hydrogen bonds forming between the main chain peptide groups of the same polypeptide chain
Tertiary structure of proteins
Formed by interactions of side chains of various amino acids. Some proteins are complete here
Quaternary structure of proteins
Proteins incorporate multiple polypeptide subunits (more than one amino acid chain is present in this chain)
In what is the mass of proteins determined?
Daltons
1 Dalton = mass of 1 hydrogen atom
What do carbohydrates consist of?
Carbon, Hydrogen and Oxygen
How are carbohydrates produced?
During photosynthesis in plants, in the form of mono- and polysaccharides. Light energy is converted to sugars by using CO2 and water.
Examples of monosaccharides
Hexose (6 carbons)
- Glucose, Fructose, Galactose
Pentose (5 carbons)
- Arabinose, Ribose, Xylose
Examples of disaccharides
Maltose
Sucrose
Lactose
Examples of polysaccharides
Amylose
Amylopectin
Starch (consists of amylose and amylopectin)
Cellulose
Hemicellulose
Glycogen (stores energy in animals and fungi)
What are lipids responsible for?
Lipids are responsible for energy storing in cells and also act as structural components of cell membranes
What are fats?
Esters of fatty acids and glycerol that are soluble in organic solvents and insoluble in water.
What are steroids?
Microbes with enzymes that mediate specific hydroxylations or dehydrogenations
What is cholesterol?
A steroid that is produced in the liver and that is required to build and maintain membranes
What is cortisone?
Cortisone is released during stress and suppresses the immune system
What is transesterification?
Transesterification is the process of exchanging the organic group of an ester with the organic group of an alcohol
What is biodiesel?
It is a fuel that consists of mono-alkyl esters of long-chain fatty acids derived from plant oils and animal fat
Through which process is biodiesel produced?
Transesterification
Sources of biodiesel
Plant oils - Soy - Canola - Palm oil - Tallow - Lard Waste oils - Restaurant oil - Old lubricating oil
How is biodiesel obtained from these oils?
All these oils and fats consist mainly of triglycerides so the esters are thus obtained from them
What are triglycerides?
Esters that consist of 3 fatty acids and glycerol
Name and elaborate slightly on the process by which biodiesel is produced
During transesterification, the oil that contains esters reacts with alcohol
How is biodiesel produced?
- Free fatty acids are removed prior to the addition of a transesterification catalyst (NaOH, POH). (Leftover concentration of ffa should not be more than 5%)
- During transesterification, the oil that contains esters reacts with alcohol (mainly methanol) to produce different esters.
oil (Ester) + alcohol = esters (biodiesel) + glycerol (alcohol) - Separation of the resulting biodiesel and glycerol takes place in a separation funnel with the less dense biodiesel on top and the mostly dense glycerol at the bottom.
How is it possible to separate biodiesel and glycerol?
Glycerol is an alcohol and alcohols are polar.
Biodiesel is nonpolar.
These products will thus not mix.
Why do free fatty acids need to be removed before transesterification?
To prevent soap formation
If there is a high concentration of free fatty acids in the feed (above 5%) how can biodiesel still be produced?
Through the esterification of the free fatty acids with an acid as catalyst. Transesterification of the ffa and an alcohol then produces biodiesel and water. The problem with this is that water formation then takes place, which formed the ffa in the first place. Heat is required to remove that water again.
What are nucleotides?
They are the building blocks of RNA and DNA.
What do nucleotides consist of?
Nucleobase
Sugar (ribose or deoxyribose)
Phosphate
Basis
RNA vs DNA
DNA is double stranded whilst RNA is single stranded.
DNA is longer than RNA.
RNA consists of hundreds of bases whilst DNA can have 3 billion bases.
Why should a cell’s composition differ from its environment?
If a living cell reaches thermodynamic equilibrium it will die. Energy must be consumed to avoid thermodynamic equilibrium.
