16-09-21 - Introduction to Biological Molecules Flashcards
What are ionic bonds?
How do ionic bonds form?
What are properties of ionic bonds?
- Ionic bonds are intramolecular bonds that involve the gaining and loss of electrons
- They form between the electrostatic attraction between the positive and negative ion
- They are soluble in water and not very strong
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Why is ion concentration important in cells?
- It is critical to maintain ion concentration in in and out of cells to ensure the cell works properly and has the nutrients it requires to function
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What are covalent bonds?
How are they formed?
And what are some properties of covalent bonds?
- Covalent bonds are intramolecular bonds that involve sharing electrons
- Covalent bonds determine the shape of the molecule
- Atoms find the ideal separation distance where electrostatic forces are maximal
- Stronger than ionic bonds
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What is a polar bond?
How do they form?
What is an example?
- Polar bonds are types of covalent bonds in which atoms with different electronegativities share electrons.
- This results in the electrons being closer to one of the atoms
- An example of this are polar covalent bonds in water, where the electrons sit closer to oxygen, as it has a higher electronegativity.
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What is a hydrogen bond?
And how do they form?
What is an example?
- Hydrogen bonding is the strongest intermolecular force there is
- It is present when an H is bonder to an O, F OR N in a molecule and is formed between The H in one molecule and the O, F OR N in another molecule.
- This causes the atom with the highest electronegativity value (O, F OR N) to be slightly negative (delta -) and vice versa
- Present in water
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What is Van der Waals forces?
- Weak intermolecular interaction between transient clouds of charges in molecules due to the movement of electrons.
- Causes molecules to be further or closer due to the repel/attraction based on where the electrons are in the molecule
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What are sugars general formula?
What are some properties of sugars?
How are sugars joined together?
What do they form?
And what can sugars be used for?
- Sugars have the general formula (CH20)n
- Can adopt different shapes and compounds (different enzymes for glucose and fructose despite same general formula – structural isomers)
- Sugars can be joined together to form carbohydrates via condensation
- Glucose can be stored as energy in the form of glycogen in muscles (local use) and the liver (to enable glucose to be supplied to all of the body.
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What are some properties of fatty acids?
How can they be stored?
What are they used for in the body?
- Fatty acids can be saturated (full of hydrogen – rigid) or unsaturated (C-C double bond – more flexible)
- Fatty acids are amphipathic, meaning they have both hydrophilic (polar end) and hydrophobic (long chain of hydrocarbons) parts
- Fatty acids can be stored as triacyl glycerol, which can be broken down into fatty acids and glycerol.
- The glycerol can give glucose which can give energy via glycolysis
- The fatty acids can break down to from acetyl-coA which can feed into the Kreb cycle and give energy.
- Fatty acids are also important components of the cell membrane
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What is the structure of steroids like?
How are they formed?
What are precursors for steroids?
- Steroids consist of 4 fused carbon rings with functional groups attached.
- They can be synthesised in the body
- Lanosterol can be converted into cholesterol, which is an important precursor for a lot of steroids
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What is the structure of amino acids like?
What varies between amino acids?
What 4 things can they be used for?
- (from amino acids view) A centre Carbon surrounded by an amino group on the right a Hydrogen on top, a carboxyl group to the left and the R-group at the bottom
- The R-group is the variant between amino acids and determines what kind of properties the amino acid will have, such as being hydrophilic/hydrophobic or being soluble in water.
- Amino acids can be polymerised into a peptide chain via peptide bonds
- Amino acids can also be sources of energy, neurotransmitters (e.g glutamic acid) and can act as pre-cursors for other molecules (e.g glycine for porphyrin ring used for haemoglobin)
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What is the structure of nucleotides
What 5 things can they be used for?
- Nitrogen ring, linked to a 5-carbon sugar (usually ribose or deoxyribose) linked to phosphate groups
- Nucleotides can act as short-term energy stores (ATP and GTP)
- Nucleotides can act as a store of electrons – NAD, NADH reducing store for biosynthesis or ATP reduction
- They can act as cofactors for enzymes (coenzyme A) – usually non-protein component required for activity of that enzyme.
- Nucleotides can also act as signalling molecules e.g Camp
- Nucleotides are the building blocks of nucleic acid (DNA or RNA)
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What are hybrid biomolecules?
Why do they exist?
Give some examples
- Hybrid biomolecules are combinations of different biomolecules together.
- They are important sources of diversity - contributes to the 3D shape and properties of molecules (such as blood groups)
- The addition of different biomolecule groups can help to stabilise the structure
- There are glycoproteins (sugar and protein) and glycolipids (sugar and fat)
- Each biomolecule in the hybrid can exist in different proportions e.g peptidoglycan has a short peptide and long chains of sugars – important components of bacterial cell wall.
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How do R groups of amino acids influence protein folding?
- The protein will fold in a way so that the core of the protein contains Hydrophobic R- groups so that they are away from the aqueous environment and Hydrophilic R groups are at the surface
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What determines different blood groups?
What happens if a blood transfusion with he incorrect blood type is made?
- Blood group is determined by the sugars added to the lipid groups of antigens on red blood cells
- Different antigens for each blood type have additional, fewer, or different components than antigens for other blood types.
- If a blood transfusion with the incorrect blood type is administered, this will trigger an immune response, as the body perceives these antigens as a threat.
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How do viruses utilize these biomolecules to function?
How are vaccines made to counter viruses?
What are the challenges?
- Viruses are coated by glycoproteins which they use to bind to host cell receptors
- Vaccines are made by identifying and raising anti-bodies against these glycoproteins
- The protein part of the biomolecule is easy to identify, but not the sugars.
- The virus can evolve and alter its sugar units in order to evade detection.
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