5 Written questions
5 Matching questions
- Fe-S protein
A strong protein which can provide strength and/or flexibility found in animal tissue.
- b The name by which the cell membrane of a plant is sometimes known.
Best known for their role in the oxidation-reduction reactions of mitochondrial electron transport. Both Complex I and Complex II of oxidative phosphorylation have multiple Fe-S clusters. They have many other functions including catalysis as illustrated by aconitase, generation of radicals as illustrated by SAM-dependent enzymes, and as sulfur donors in the biosynthesis of lipoic acid and biotin. Additionally some Fe-S proteins regulate gene expression. Fe-S proteins are vulnerable to attack by biogenic nitric oxide.
The process by which substances or pathogens are taken in to a cell by engulfment by a vesicular structure surrounded by cell membrane.
Membrane lined gap junctions which cross cell walls in plants.
5 Multiple choice questions
The form of enzyme regulation brought about when an effector molecule binds to an enzyme at it's allosteric site, thus bringing about changes in it's conformation and therefor effecting it's ability to function. This form of regulation is immediately effective and also immediately reversible.
A generic term for the N- or O-substituted derivatives of neuraminic acid, a monosaccharide with a nine-carbon backbone. It is the sugar present on cadherins and N-CAMS which gives them their negative charge. It is also the name for the most common member of this group, N-acetylneuraminic acid (Neu5Ac or NANA). Sialic acids are found widely distributed in animal tissues and to a lesser extent in other species ranging from plants and fungi to yeasts and bacteria, mostly in glycoproteins and gangliosides. The amino group generally bears either an acetyl or glycolyl group but other modifications have been described. The hydroxyl substituents may vary considerably: acetyl, lactyl, methyl, sulfate, and phosphate groups have been found.
A non-covalent complex composed of a substrate bound to the active site of the enzyme
- The name given to a growing polypeptide chain. Literally translated this word means beginning to exist or develop.
This form of secondary active transport uses the downhill movement of one solute species from high to low concentration to move another molecule uphill from low concentration to high concentration (against its electrochemical gradient). An example is the glucose symporter SGLT1, which co-transports one glucose (or galactose) molecule into the cell for every two sodium ions it imports into the cell. This symporter is located in the small intestines, trachea, heart, brain, testis, and prostate. It is also located in the S3 segment of the proximal tubule in each nephron in the kidneys. Its mechanism is exploited in glucose rehydration therapy and defects in SGLT1 prevent effective reabsorption of glucose, causing familial renal glucosuria.
5 True/False questions
Nuclear localization signal → An important control mechanism in metabolism, this is also the route of effect used by many drugs and also of many toxins.
Substrate level phosphorylations →
This shows as dark areas on the eukaryotic nucleas; it is densly packed chormatin (DNA and protein complex) which cannot be transcribed.
Alanine (abbreviated as Ala or A) is an α-amino acid with the chemical formula CH3CH(NH2)COOH. It can be synthesized from the pyruvate intermediate of the TCA cycle. The L-isomer is one of the 22 proteinogenic amino acids, i.e., the building blocks of proteins. Its codons are GCU, GCC, GCA, and GCG. It is classified as a nonpolar amino acid. L-Alanine is second only to leucine in rate of occurrence, accounting for 7.8% of the primary structure in a sample of 1,150 proteins.D-Alanine occurs in bacterial cell walls and in some peptide antibiotics.
3 useful functions of TCA cycle → Also called SRP, this is an abundant, cytosolic, universally conserved ribonucleoprotein (protein-RNA complex) that recognizes and targets specific proteins to the endoplasmic reticulum in eukaryotes and the plasma membrane in prokaryotes.
Glutamate dehydrogenase →
Glutamate dehydrogenase is an enzyme, present in most microbes and the mitochondria of eukaryotes, as are some of the other enzymes required for urea synthesis, that converts glutamate to α-Ketoglutarate, and vice versa. In animals, the produced ammonia is, however, usually bled off to the urea cycle. In bacteria, the ammonia is assimilated to amino acids via glutamate and amidotransferases. In plants, the enzyme can work in either direction depending on environment and stress. Transgenic plants expressing microbial GDHs are improved in tolerance to herbicide, water deficit, and pathogen infections.They are more nutritionally valuable.