Cells from which all forms of life on earth believed to be derived?
Variation in these acids is believed to have provided the variation on which natural selection could act.
The formation of these provided a stable environment for metabolism.
Intracellular compartments and transport systems
Development of these allowed the size of eukaryotic cells to increase.
Cell differentation and specialization into organ systems
It was these evolutionary emergences that brought about the appearance of multicellular organism and neccessitated the development of intercellular signalling and transport systems.
Species studied in depth because their study allows greater understanding of of specific biological processes.
A type of phagocyte which is an example of a cell type that remains motile in adult multicellular organisms.
Name two cells of the blood vessels that can become motile during wound healing.
Name a male cell which remains motile in the adult multicellular organism.
Cell division and intracellular transport
Name 2 basic functions of the cell cytoskeleton.
Developement of larger cells and intracellular transport systems
What evolutionary opportunities did the development of the cytoskeleton confer?
Specialized shaping, differentation and cell motility.
What three advanced functions does the cell cytoskeleton enable?
Cell differentation via selective expression of genes.
Intercellular signalling systems.
Cell receptors which enable intercellular communication.
What properties do the cells of multicellular organism have which the cells of unicellular eukaryotic organisms do not (name four examples)?
Oxygen, carbon, hydrogen, nitrogen, calcium, phosphorus, potassium, sulphur, sodium, chlorine
Name the 10 main elements which make up the human body (in order of mass from largest to smallest contributor).
Cobalt, copper, iodine, iron, managnese, zinc
Name six trace metallic contributors to human body mass (in alphabetical order).
What percentage of body mass is derived from water?
In liquid form how many hydrogen bonds on average does each water molecule have?
Solutes that are readily disolved in water and are charged and polar are known as?
Lipids and proteins of the cell membranes
Which molecules in a cell are hydrophobic?
When molecules have two concentric hydration shells around them what terms could be used to describe them?
What causes uncharged polar compounds to be hydrated?
This term is used to describe molecules which are both polar and non-polar.
What stabilizes the aggregates of amphipathic molecules in an aqueous environment?
What is the major molecular constituent of every cell in every organism?
Substances which are uncharged and non-polar are known as?
What is the valency of carbon?
How many covalent bonds can carbon form?
Word used to describe the three dimensional shape or conformation of a molecule.
Molecules which rotate the plane of plane polarized light are known as?
A mixture comprised of equal amounts or R and S (or D and L) enantiomers is known as?
What stereochemical conformations have all amino acids and all naturally occuring proteins been found to have (D or L)?
What is the name of the method used to deduce the structure of proteins by using the ability of their chiral centres to defract plane polarized light?
Four groups bonded to a carbon take up a what arrangement?
What is the name given to a carbon atom bonded to four different groups/atoms?
Aldehydes, amides, esters, ketones and carboxylic acids
What five functional groups are considered carbonyl?
The simplest form of carboxylic acid which is a vital building block in the synthesis of large complex molecules such as long-chain fatty acids.
The sulfur containing coenzyme that transfers acetyl groups between metabolic intermediates.
An acetyl group (CH3CO-) covalently bound to the sulfur-containing coenzyme A (CoA)
The first, anaerobic stage of glucose oxidation, in which glucose is converted into pyruvate or lactate. It takes place in the cytosol.
Tricarboxylic acid (TCA) cycle
The series of metabolic steps involved in the breakdown of acetyl CoA to carbon dioxide and water under aerobic conditions in the mitochondria of cells. Also known as the Krebs cycle.
Simple sugars (carbohydrates) with typically five or six carbon atoms and having the general formula (CH2O)n, where n=3-8. Common versions of these are glucose, fructose and ribose.
The sugar which contains an aldehyde group as its carbonyl.
The sugar which contains an ketone as it's carbonyl (for example fructose above).
A carbohydrate polymer consisting of up to 15 covalently linked monosaccharide residues. These can often be found covalently bound to the proteins of cell surfaces.
Large carbohydrate polymer consisting of many sugar monomers (monosaccharide residues) joined together. These may be storage molecules (such as glycogen and starch) or structural molecules (e.g cellulose in plant cell walls).
A compound that contains both an amino group (-NH2) and a carboxyl group (-COOH). There are about 20 naturally occuring varieties of these, which are particularly important in living organisms; these have the general formula as pictured when R represents one of about 20 different groups (side-chains). These are the monomers from which proteins are synthesized.
At physiological pH amino acids exist in this form, having both a positively and negatively charged group.
A molecule consisting of two or more amino acids linked by a peptide bond.
The covalent C-N bond that links amino acid residues in a peptide or polypeptide; formed in a condensation reaction between the acidic carboxyl group (-COOH) of one amino acid and the basic amino group (-NH2) of another amino acid.
A sequence of amino acids joined together in a linear chain.
Linked amino acids are frequently referred to as this.
The name also used to describe the carboxyl end of an amino acid, this is the end at which amino acids are added.
The amino end of an amino acid, from which by convention numbering of a residue always begins.
The monomer that is the building block of nucleic acids. These are composed of a base, a pentose sugar molecule (ribose in RNA, deoxyribose in DNA) and a phosphate group. The bases of DNA are adenine (A), guanine (G), cytosine (C) and thymine (T), those of RNA are adenine (A), guanine (G), cytosine (C) and uracil (U).
A general name for the nitrogen-containing organic group present in nucleic acids. In the cell these do not generally occur in the free form but are combined with ribose or deoxyribose to form nucleosides.
adenine, cytosine, guanine, thymine
Name the four different bases in DNA (in alphabetical order).
A type of nitrogenous base with a single ring structure, e.g. cyrosine, thyamine and uracil.
A type of nitrogenous base with a double ring structure e.g. adenine and guanine.
These are the equivalent to a nucleotide which has had the phosphate group removed and are composed of a nitrogenous base linked to a pentose sugar (ribose or deoxyribose).
The state when the overall intracellular and extracellular concentration of ions either side of the semipermiable membrane is in balance, i.e. there is no net passive flow of ions between the two environments (unless a flow is required to fuel a specific process).
What is the general voltage difference between the inside of a mammalian cell and the outside?
What would be the correct representation of protons in biochemical reactions (note it's not H+)?
Is the concentration of potassium lower inside the cell than it is outside the cell (yes or no answer)?
Is the concentration of sodium lower inside the cell than it is outside the cell (yes or no answer)?
Why is an internal ionic environment important to a cell?
What is the name of the energy consuming process required to pump ions against a concentration gradient?
The active transport of more than one type of ion (one along it's concentration gradient the other against it's concentration gradient) across the cell membrane via ion channels into the cell.
Occurs via an integral membrane protein involved in secondary active transport of two or more different molecules or ions (i.e., solutes) across a plasma membrane in opposite directions. During this type of transport one species of solute moves along its electrochemical gradient, allowing a different species to move against its own electrochemical gradient. This movement is in contrast to primary active transport, in which all solutes are moved against their concentration gradients, fueled by ATP.
A process of passive transport, facilitated by integral proteins. This type of transport is the spontaneous passage of molecules or ions across a biological membrane passing through specific transmembrane integral proteins. It may occur either across biological membranes or through aqueous compartments of an organism. This allows the passage of polar molecules that would otherwise be unable to cross the lipid membrane.
The process of stabilizing the pH of a solution or a cell. This is acheived by the use of buffers (which donate donate protons/are weak acids) to control the pH concentration. An example of a buffer is HCO₃⁻ (pictured).
What is the most significant (with regards importance) small metal trace element?
From which amino acid is thyroxine formed?
The cluster of groups surrounding and forming non-covalent bonds with a coordinated metal ion in an organic molecule, e.g. the porphyrin ring that coordinates the Fe²⁺ ion in haem.
One of a set of non-covalent bonds that holds a metal ion in an organic molecule.
What two ions are regulated by transport processes, serve as signals for many vital intracellular processes and are activators for key enzymes?
Several key small organic molecules such as ATP, rely on this to aid with short term energy storage.
A way of representing reactions, where the reactions are reversible and proceed to the point where the forward and reverse reactions occur at the same rate. The concentrations of the reactants at equilibrium are defined as the equilibrium constant.
Law of mass action
States that the forward rate (Kf) and the reverse rate (Kf) of an equilibrium reaction depend on the quantities of each of the reactants.
(Keq) The ratio of the concentration of products and reactants when a reaction has reached equilibirum.
A reaction that occurs spontaneously because it releases energy and/or increases the entropy (disorder) of the system.
A reaction that although thermodynamically favourable proceeds slowly.
The rate of change in a process or reaction.
The study of energy and its transformations. The first law of this states that energy is neither created nor destroyed, although it may be converted from one form into another (e.g. chemical bonds into heat). The second law states that if the overall change in entropy (S) during a reaction is positive the the process or reaction will proceed spontaneously.
The situation where intermediates of a metabolic pathway remain at a constant level because they are replenished at the same rate as they are used up.
Le Chatelier principle
This prinicipl states that when a system in chemical equilibrium is subjected to an external constraint, the system responds in a way that tends to oppose the effect of the constraint. 'If a system at equilibrium is subjected to a change in pressure or temperature or the concentration of a component, there will be a tendency for a net reaction in the direction that reduces the effect of this change'.
The degree of ionization or dissociation of a molecule or functional group at a given pH is determined by its?
When the solution pH is above the pK of the molecule does the carboxyl group exist predominantly in the ionized or unionized form (answer ionized/unionized)?
When the solution pH is below the pK of the molecule does the carboxyl group exist predominantly in the ionized or unionized form (answer ionized/unionized)?
A solution consisting of a weak acid and its conjugate base, or a weak base and its conjugate acid, which resists changes in pH. In biological systems these prevent dangerous extremes of pH.
Do the H⁺ ions produced during exercise raise or lower blood pH (answer lower/raise)?
Does exhalation of CO₂ and water from the lungs lower or raise blood pH (answer raise/lower)?
An electrostatic interaction between a positively charged group on one molecule and a negatively charged group on another. These bonds are potentially quite strong but in aquaeous environments the water shell around charged molecules spreads the charge such that the attraction is reduced.
Another term for the groups or ions involved in an ionic bond.
Another term for an ionic bond.
Van der Waals forces
Weak non-covalent interactions between molecules of complementary shape, due to oscillating dipoles on the interacting molecules. These are only generated when the molecules are very close to each other and disturb each others electron clouds, however too close and the molecules will be repulsed thus the reason complementary shape is crucial.
A measure of how strongly one molecule binds to another (also see equilibirum dissociation constant).
A molecule or ion that binds to a protein at a specific binding site. Different proteins bind to a vast range of these, ranging from small ions, through small molecules to other proteins and DNA. This binding is highly specificm such that a given protein may bind to just one or two of these.
Equilibrium dissociation constant
K (subscript) D. A measure of binding affinity between two molecules, the extent to which a complex dissociates to form two seperate molecules (A & B). Large values represent weak binding, small values represent strong binding.
In terms of Ramachandran plots when the van der Waals radii have no interatomic conflicts the conformation is?
In terms of Ramachandran plots conformations requiring interatomic distances at the limit of that which is permissable is defined as?
In terms of Ramachandran plots conformations that require any two non bonding atoms to be closer to each other than their van der Waals radii as defined as?
This type of DNA has 10 bases per helical turn and is right handed. It also has the lowest energy of the three secondary structures of DNA. This is thought to be the general form of DNA in it's native duplex state in the cell.
This DNA has 12 base pairs per helical turn and is left handed. It has no major groove and is believed to form only transiently within genomic DNA during transcription.
This DNA has 11 base pairs per helical turn and is right handed. Predominantely found in double stranded RNA.
This type of topoisomerase causes the breaking (regional relaxation/increased supercoiling) of one strand of the DNA.
This type of topoisomerase causes the breaking (regional relaxation) of two strands of DNA by breaking the deoxyrybose phosphate back bone. This also has the ability to knot and unknot DNA as well as catenating (linking) and decatenating circular double stranded DNA.
Nucleic acid sequences that code for proteins.
Nucleic acid sequences that do not code for proteins, often self spliced by ribozyme activity in the immature mRNA.
A Southern blot is a method routinely used in molecular biology for detection of a specific DNA sequence in DNA samples. Southern blotting combines transfer of electrophoresis-separated DNA fragments to a filter membrane and subsequent fragment detection by probe hybridization.
(fluorescence in situ hybridization) a cytogenetic technique developed by biomedical researchers used to detect and localize the presence or absence of specific DNA sequences on chromosomes.
It uses fluorescent probes that bind only to parts of the chromosome with which they show a high degree of sequence complementarity. Fluorescence microscopy can be used to find out where the fluorescent probe bound to the chromosomes. Often used for finding specific features in DNA for use in genetic counselling, medicine, and species identification. Can also be used to detect and localize specific mRNAs within tissue samples. In this context, it can help define the spatial-temporal patterns of gene expression within cells and tissues.