Chemical Components of Cells Flashcards
Lecture 2
What element is life based on
Life is based on carbon atoms and chemical reactions that take place in solution. This is all dominated and coordinated by polymeric molecules.
96.5% of living organisms weight consists of just…
- Carbon
- Nitrogen
- Oxygen
- Hydrogen
Cells contain 4 families of small organic molecules
- Sugars
- Fatty Acids
- Amino Acids
- Nucleotides
The building block of the cell is Sugars. What is the larger unit of the cell?
Polysaccharides
The building block of the cell is Fatty Acids. What is the larger unit of the cell?
Fats/ Lipids/ Membranes
The building block of the cell is Amino Acids. What is the larger unit of the cell?
Proteins
The building block of the cell is Nucleotides . What is the larger unit of the cell?
Nucleic Acids
Whats is the main use of sugars
Energy source for cells and subunits for polysaccharides
What are the different sugar types
Monosaccharides Disaccharides Polysaccharides Aldoses Ketoses Oligosaccharides
How are monosaccharides formed
Condensation and/or Hydrolysis
How are Disaccarides formed
Formed by condensation and/or hydrolysis
How are polysaccharides and oligosaccharides formed
Polymerisation of monosaccharides leads to the formation of oligosaccharides and polysaccharides
What structure do sugars exist in
Ring structures as aldehyde/ketone groups of sugar react with -OH(hydroxyl) group
Small oligosaccharides can link with lipids or proteins to form?
Glycolipids or glycoproteins
Aldoses and Ketoses have…
An aldehyde group (CH=O) or a ketone group.
Fatty acids - Main use
Main components of cell membranes. They are used for their construction and the membranes are largely composed of phospholipids
The two main parts of the fatty acids structure
Hydrocarbon tail and a hydrophilic head
The Hydrocarbon tail can vary
These can be saturated or unsaturated. This accounts for the difference between hard and soft margarine. The addition of hydrogen to unsaturated bonds results in saturated C-C bonds, increasing the melting point thus “hardening” it.
Fatty acids have concentrated food reserves in cells
-These are stores through ester linkage to glycerol which forms triglycerols
These are 3 fatty acid chains joined to 1 glycerol molecule
- They are stores in the cytoplasm of cells
- 6 times more energy than glucose by weight
Fatty acids are Amphipathic.
What does this mean?
They are both hydrophillic and hydrophobic. This induces the membrane forming ability, produces a lipid bilayer
Amino acids are…
The sub units of proteins
Therefor proteins are just amino acid polymers
Amino acids all possess what groups
Carboxylic acid group
Amino Acid Groups
This produces polarity
Amino acids all contain how many carbon atoms
A single carbon atom
alpha- carbon
Where does the chemical varieties in amino acids come from
The side chains
What bond is between amino acids
Peptide bond.
This means a chain of amino acids is a peptide
What are the main units of Nucleotides
They are the subunits of DNA and RNA
What is the structure of Nucleotides
They are nitrogen containing ring compounds (the base) linked to a 5 carbon sugar. They carry at leas 1 phosphate group.
The bases come together in different orders which create different nucleotides
-L- and D- optical isomers… .
only L- isomers in proteins
-side chains can be basic, acidic, polar, non-polar
Bases in nuceotides are either
Purines (guanine(G) + adenine(A))
OR
Pyrimidines (cytosine( C) +thymine(T) + Uracil(U))
What do nucleotides act as
Short term carriers of energy
Nucelotides come together to form
Adenosine Triphosphate (ATP) this is made of 3 phosphates linked by the energy rich phosphoanhydride bonds. When there rupture energy is released
The most fundamental role of nucleotides is
Storage and retrieval of biological information through the construction of nucleic acids. These are linked by phosphodiester bonds.
Ribose gives ribonucleic acids (RNA) and deoxyribose gives deoxyribonucleic acids (DNA)
- DNA double stranded -> GATC,
- RNA single stranded -> GAUC
The linear sequence encodes information
-G and C have triple bond but A=T is only double bond (or A=U)
