Molecular Building Blocks 04.10.22 Flashcards
What 4 components make up living systems?
Hydrogen, Oxygen, Carbon and Nitrogen (phosphorus)
What are the key features of a living organism?
- one or more cells
- capable of reproduction
- responds to the environment
- adapting and changing (& inheritance)
- require a source of energy
- growth and development
What are some examples of single cell life?
Bacteria, simple fungi, Amoeba. Can still interact with the environment
What is simple multicellular?
Still interacts with the environment, passes on information, divides and grows. Can form a tissue that lives
What is the difference with humans being multicellular?
We are multicellular as we have tissues and different types of tissue that communicate with each other and specialise to carry out a specific function. That is controlled by DNA and gene expression and the interaction with proteins and other molecules.
What is a macromolecule?
Simple molecules built up into large, complex molecules e.g. sugars, lipids and amino acids
They can control osmotic pressure that can be used structurally for things like collagen
E.g. Haemoglobin, DNA, glycogen, Rhodopsin, Collagen
What is the structure of macromolecules?
Heterogeneous (many different types) Often specific conformations are associated to definite functions
What are some properties of water?
- Universal solvent
- Polarity
- Hydrogen bonding
- Liquid over a range from 0-100 degrees C
- Achieves maximum density at 4 degrees C
Can water dissolve ionic and polar compounds?
Yes, it is excellent because of its polarity. It will be attracted to ions with a positive or negative charge as the oxygen is electronegative itself
What is a Hydrogen bond?
Not a covalent bond, weak, but very important in protein and DNA structures and responsible for the unusual properties of H20. Lots of H-Bonds together make a structure strong.
How is a hydrogen bond formed?
Electronegative atoms such as Oxygen or Nitrogen can attract Hydrogen atoms (protons) from other molecules. They partially share this proton, leading to a mutual attraction between the two atoms.
What does water not interact with?
-Non-polar substances
-Lipids
-Aromatic groups, with a benzene ring
These are called hydrophobic compounds
When and how did life begin?
- 3.5 billion years ago
- Defined through Mrs Nerg type processes.
- One of the earliest steps of life was the segregation of life inside a lipid bilayer (hydrophobic)
- At the same time viral replication was also arising at the same time
What do many monosaccharides form?
Polysaccharide
What do nucleotides joined together form?
Nucleic acid
What do amino acids bonded with a peptide bond together form?
Protein
What are carbohydrates?
Cn(H20)n
Made of Carbon, Hydrogen and Oxygen
We can have mono, di, oligo (a few) or polysaccharides
E.g. starch and glycogen
What are monosachharides?
- Chain of carbons, hydroxyl groups, one carbonyl group
- An aldose has an aldehyde
- a ketose has a ketone
E.g. Glucose (hexose: 6 Carbon) , ribose (pentose), erythrose (tetrose)
How are the 6 C and 5 C sugars arranged?
Normally in a cyclised (ring) structure, due to the OH and H group
How can sugars be derivatives?
Derivative: sugar molecules that have been modified with substituents other than hydroxyl groups
- Amino-sugars: containing an amino group
- Alcohol-sugars e.g. sorbitol
- Phosphorylated: makes glucose polar
- Sulphated: sulphate groups
What is a glycosidic bond?
- Hydroxyl group of a monosaccharide can react with an OH or an NH group, to form glycosides
- O-glycosidic bonds (oxygen) from di and polysaccharides
- N-glycosidic bonds (nitrogen) are found in nucleotides and DNA (as bonds to an amino group)
What is an Oligosaccharides?
Contain 3 – 12 monosaccharides.
Product of digestion of polysaccharides, or part of a complex protein or lipid.
What is a Polysaccharides?
Formed by thousands of MS joined by glycosidic bond.
Glycogen – branched polysaccharide formed of glucose residues.
What are nucleotides?
Building blocks of DNA.
Made from nitrogenous base + sugar + phosphate.
