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
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
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
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.
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
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
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.
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
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
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)
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)
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.
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
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.
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.
How do changes in structure disrupt function of biological processes regarding enzymes?
- An enzyme or its substrate become denatured, then they will no longer be able to fit together and the enzyme can’t break down its substrate.
What can errors in protein folding cause?
What diseases can error in protein folding cause?
- Can results in dysfunctional proteins accumulating and forming a precipitate, which underpins a lot of these diseases
What can damage in DNA structure cause?
- If damaged, the DNA can mutate when that section of the DNA comes to be replicated
- This can cause mutations, which can be harmful, beneficial, or neutral
