Flashcards
Whawell 1
Cards in this deck (117)
- 1What are incapable of being divided?Atoms
- 2What is a tissue?Group of similar cells with common function
- 3What are the 3 types of non-covalent bonds which are critical in biology/Hydrogen, electrostatic, Van der Waals
- 4How is a hydrogen bond created?Hydrogen covalently bonded to an electronegative atom
Then a second interaction with another strongly electronegative atom - 5What two things can weaken electrostatic bonds?Salt and water
- 6What are the finctions of lipids?Cell membranes
Storing energy
Insulation, protection, absorbing shocks
Controlling cell activity - 7How many rings does a cholestrol/steroid hormone have4
- 8What are the functions of carbohydrates?Store short-term energy
Structural materials
Molecular tags - tagged on to proteins for identification
Contribute to the structure if nucleotides - 9What are the functions of proteins?- Structure
- cell transport
- muscle contraction
- signalling
- Enzymes
- Cell attachment - 10How many amino acids in one polypeptide/20
- 11What are the 4 different types of RNA?Messenger, transfer, ribosomal and viral
- 12Functions of nucleotides?Stores information needed to control and build cells
- 13What is the catabolism process?- Breaking down of energy yielding nutrients e.g. fats, carbohydrates, proteins
- To produce Energy poor end products e.g. water, carbon dioxide and ammonia
- Also produces chemical energy ATP and NADPH - 14What's the process of anabolism?Using chemical energy to build up precursor molecules
- amino acids, sugars, fatty acids, nitrogenous bases
- Also use the chemical energy from the catabolism and precursors to make proteins, polysaccharides, lipids and nucleic acids - 15What is dentin made up of?mineralised collagen
Dentin sialoproteins
Dentin phosphoprotein - 16What 3 things is enamel made up of?- amelogenins
- ameloblastins
- enamelins - 17What are the different biomolecule classes?Lipids
Proteins
Carbohydrates
Nucleic acids - 18What is the cytoskeleton?Network of protein polymers within cells
Polymers are dynamic - able to assemble and disassemble - 19What are the 3 different types of polymers in cytoskeleton?1. Actin filaments (microfilaments)
2. Intermediate filaments
3. microtubules - 20What are the functions of the cytoskeleton?- Provide mechanical support
- Shape and organisation of the cell
- Cell movement
- Organelle movement - 21Where's actin distributed in cells?Just under the surface of the cells
- 22What does actin form?Things that stick out:
- microvili
- lamellipoclia
- filopoclia - 23What types of cell movement does actin allow?Phagocytosis
Cytokinesis
muscle contraction - 24What are the two different types of actin?Monomer G - globular
Polymer F - filamentous actin; narrow, highly organised, concentrated beneath membrane - 25Actin polymerisationNucleation - G actin monomers slowly aggregate till a stable nucleus is formed
Nucleus elongates by addition of monomers to both of its ends
The positive end elongates faster
Having oppositely charged ends means that when things move along, know which way to go.
The resulting F - actin reaches steady state equilibrim - 26What do actin cross-linking proteins do?Organise actin filaments into dynamic and complex subcellular scaffolds
- this has mechanical functions
Cell motility and adhesion - 27What are myosin proteins? What are they used for?Motor proteins that move along acting filaments while hydrolysing ATP
Muscle power, cell contraction, migration and vesicle transport - 28What does cytochalasin do?Blocks bacterial invasion
Blocks actin polymerisation
Blocks endocytosis - 29What are intermediate filaments and what do they do?Nuclear and cytoplasmic meshwork
Polymers of protein subunits
- rope-like filaments
-widely distributed
- mechanical strength - 30What are examples of intermediate filaments?Vitementin
keratin
desmin
neurofilaments
lamin - 31What are keratins made up of and how does that allow identification?They are hetropolymers of type I and type II proteins
Pairing is tissue specific
Can identify where you are in the body by looking at the type of hetropolymer
Pairing is predictive of epithelial proliferative and differentiation status - 32How can you use antibodies to identify proteins?- primary antibody binds to antigen
- Secondary antibody binds to the primary antibody
- Enzyme linked to secondary antibody converts substrate to coloured product - 33What can cell identification tell you?the differentiation status of the cell
- 34What are the different roles of microtubules?- structural support to the cell
- Attach to chromosomes (centromere), motors walking along pull the chromosome apart - 35What are kinesins and dyneins? What else can dyeins do?Kinesins - proteins belonging to motor proteins that move along microtubule filaments by ATP
Dyneins - family of cytoskeleton motor proteins that move alonf microtubules in cells
Can also transport cellular cargos, provides forces and displacements are important in mitosis - 36What are mitotic spindle fibres made up of?Microtubule and microtubule dependent motor proteins
- 37Where do mitotic spindle fibres attach to on the chromosome?At kinetochores
- 38What type of microtubules make up cillia and flagella?axoneme
Interactions with bundle allows them to beat back and forth - 39What to microtubules direct?Actin assembly and force generation
- 40What are the 6 different types of cell junctions?Tight junction
Adherens junction
Desmosome
Gap junction
Hemidesmosome
Actin-linked cell matrix junction - 41What's the difference between adherens junction and desmosome junction?Ad - connects actin filament bundle in one cell with that in the next
Desmosome - connects intermediate in one cell to those in the next - 42What does the gap junction do?Allows the passage of small, water soluble molecules cell to cell
- 43What's the difference between Hemidemosome and actin-linked cell matrix junction?Hemi - anchors intermediate filaments in a cell to ECM
Actin-linked cell matrix - anchors actin filaments in a cell to ECM - 44What was the Schleiden and schwaan cell theory?- Organisms composed of cells
- Units smaller than cells are not alive
- Arise by division - 45What 3 places did molecules that made life come from?- Atmosphere
- Deep sea vents
- Impact theory - meteorites - 46What molecules are in the primordial soup?Methane, ammonia, water, CO2, CO, phosphate
- 47What happened in the Miller-Urey experiment?Contains; hydrogen ammonia, methane
one flask water
one flask of electrodes
Within one week, carbon amino acids
Sugars, lipids, and nucleotide precursors - 48What's the RNA world hypothesis?RNA molecules to have been the precursors to all current life on earth
RNA makes up genetic info and enzymes no protein - 49What do peptidyl transferase ribozymes do and what is special about them?Form peptide bonds between adjacent amino acids using rRNA's during translation
The only enzyme made up of ribonucleotides - which drive protein synthesis - 50What are the 2 molecular compartments that make up the protocell?RNA replicase
Fatty acid membrane vesicle - 51What's different in a living cell?Ribozyme - synthesises lipids
Membrane and genome are linked
Autonomous replication
Capable of Darwin evolution - select for the cells that make proteins - 52What's the difference in division in eukaryotes and prokaryotes?E - mitosis
P - Binary fission - 53What's the difference in reproduction in prokaryotes and eukaryotes?E - meiosis
P - transfer of DNA fragments - 54Components of eukaryotic cells:- Plasma membrane
- Nucleus with nuclear membrane
- Membrane bound organelles
- Cytoskeleton - 55What is differentiation?Series of events where cells change their phenotype
Terminal differentiation - post-mitotic, lost ability to divide - 56What type of cells are embryonic cells?totipotent cells - can form any cell in the body
- 57Cells within in the oral mucosa`Epithelial, fibroblasts, dendritic cells, endothelium cells
- 58Cells within the salivary glandsSerous, mucus, myoepithelial
- 59How are amino acids used in metabolism?Glucogenic amino acids converted into glucose through gluconeogenesis
Also ketogenic aa's converted into ketone bodies, produced by acetyl co-A in mitochondria of liver cells when no carbohydrates are available, so need energy from fatty acids - 60What are precursors?non-protein aa's
- 61What is the pK a measure of?pH at which half weak acid is dissociated
- 62What is the Henderson-Hasselbach equation?pH = pK + log [A-]/[HA]
- 63What is the isoelectric point?pH at which the net charge is 0, when the zwitter ion is most prominent
The molecule would not move In an electric field - 64Which enzyme that in the ribosome forms peptide bonds?Peptidyl transferase
- 65When do buffers work best?At their pK value
- 66What are the different chemical classifications that can be given to the protein by the R side group?Aliphatic, aromatic, sulphur containing, charged, polar, non-polar, acidic, basic
- 67What is meant by a non-polar amino acid? How do they act with water?Charge is evenly distributed
- hydrophobic tend to repel water - 68how do non-polar amino acids help I building a 3D protein structure?Drive protein folding, fold towards the inside of the globular protein to get away from water on the outside
- 69Acidic amino-acidsHave an extra carboxyl group as the side chain group
They are negatively charged at neutral pH (donate their protons)
Take part In electrostatic interactions - 70Basic amino acidshave an extra amine group in their side chain
Positively charged at neutral (accept protons) - 71What is the electrophoresis method?- Separate proteins and nucleic acids
- Load them on to gel and coat proteins with negative charge
- disulphide bonds are broken
- Proteins move towards anode according to their size
- Globular move through faster than fibrous, as they would get tangled - 72What's the 2D gel electrophoresis method?- Sample exposed to gel where pH different at one end compared to the other
- Proteins move till they're at their isoelectric point
- Then apply current in the other plane, separate them out according to weight - 73What can glycosylation do to a protein?Stabilisation
add a molecular tag
changes the behaviour - 74What can phosphorylation do to a protein?intracellular signalling,
change the charge... this changes the structure, shape and 3D shape in space, activate it - 75What do kinases and phosphates do?kinase - transfer of phosphate groups
phosphates - removes the phosphate group - 76What is meant buy a single point mutation?Change in one amino acid
- 77What are the different classifications of amino acids?Polar, non-polar, acidic, basic
- 78What are the 3 different shapes of proteins?Globular, fibrous, membrane spanning
- 79What does the conformation of the protein give to the protein?Function
Binding specificity
Flexibility
solubility
degradability
position of the side chains in 3D space - 80What are the 3 regular structures in the secondary structure?alpha helix
beta pleated sheet
beta turn - 81What makes the secondary structure more flexible?non-regular coils and loops
e.g. hinges
Regions between domains in protein, allow flexibility.
- allows domains to move relative to one another - 82What drives folding into the 3D shape?Water
Hydrophobic parts in the inside
Hydrophilic parts on the outside - 83How are alpha helices held together?By H-bonding between amino acids NH and CO groups
- 84What is the optimal shape for hydrogen bonding in a beta sheet?When bent (pleated)
- 85What is a beta turn?4 amino acids held together by hydrogen bonds
Ends of sheets form massive sheet-like structure - 86What is the tertiary 3D structure a binding site for?ligands
- 87What do chaperones help with?protein folding
Establishing proper conformation
Prevents unwanted protein aggregation - 88Why do chaperones have no water?Water would inhibit interactions
- 89What is meant by the haemoglobin tertiary structure being allosteric?When something binds, can change the conformation to either make something happen or not
- 90What type of interactions can zinc located in the active site take part in?electronic-chemical interactions
- 91What things can cause a protein to denature?pH, temperature, acids, bases, high salt, solvents
- 92How can protein miss folding lead to disease? How can they be treated?Tightly packed beta sheets, resistant to the bodies defences
Pharmaceutical chaperones - changes the shape to fold the right way - 93What are prions and what do they do?Are infectious agents composed of only protein
Fold in structurally distinct ways
Increases beta sheets, causes misfolding of proteins - can act as template
More stable with more sheets - 94What is meant by prions causing neurodegeneration?loss of structure and function of neurons
- 95What are the 4 basic cell tissues?Epithelium (covering)
Connective tissue (support)
Muscle (movement)
Nervous Tissue (control) - 96When is the thickness of the epithelium thin? When is it thick?Multiple layers where likely to be abrasions
Single thickness for absorption and secretion - 97What determines the structure and function of the connective tissueProportion of cells and ECM (fibres and proteins) and characteristics of the ECM
- 98What is connective tissue made up of?Cells and ECM (fibres and proteins)
- 99What are the different forms of connective tissue?Loose, dense, cartilage, bone, blood cells and vessels
- 100What's the difference in the uses for loose connective tissue and dense connective tissue?Loose - space packing and insulation - fatty tissue
Dense - tough fibrous tissue for protection and attachment - ligaments and tendons - 101What are the functions of bone?protection of underlying organs
Base for muscular activity - something for muscles to work against - 102Where are the two places that the epithelium branches?Around the teeth, at ovarian end of the fallopian tubes
- 103What's derived from the endoderm, what's derived from the ectoderm?endo - GI and respiratory tracts
ecto - epidermis and enamel - 104What's the basal end of the epithelium adjacent to?connective tissue
- 105What's the 4 main functions of the epithelium?Protection
Absorption
Filtration
Secretion - 106What 3 things do you use to classify epithelia?Number of cell layers
By shape
By modification - 107How is epithelium classified using number of cell layers?Simple
Stratisfied
pseudostratisfied - 108Where are simple cuboid cells found?Walls of secretory ducts in glands
- 109What is a pseudostratisfied layer and where is it found?All cells in contact with the basement membrane but they don't all reach the surface
Have cilia and goblet cells present
Found in the respiratory epithelium - 110Where are stratisfied squamous cells going to be found?places subject to high abrasion
e.g. epidermis of the skin, epithelium of the mucosa - 111What are the 4 layers of the stratisfied squamous epithelium?1. Basal - connected to connective tissue
2. Spinous - stem cells
3. Granular - waterproofing
4. superficial - keratin - 112What is meant by a keratinised epithelium?thick layer of dead cells with keratin filling each cell
- 113how is the basal layer connected to underlying connective tissue?by hesmidesmosomes
- 114What are the names of the two layers of the basal lamina that separates the epithelium from connective tissue?Lamina Densa
Lamina Lucida - 115How are glands formed?by the epithelium infolding to produce 3D structures
- 116What's the difference between exocrine and endocrine gland?exo - gland remains connected to the surface by a duct
Endo - gland is isolated and secretes directly into blood stream - 117—
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- Den 103 Flashcards on Whawell 1, created by Clelia Serra on 28/12/2016.
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