Photosynthesis, chemosynthesis and protein biosynthesis
Answers are for parents and teachers.
1
Make a table comparing photosynthesis and respiration: location, starting and final substances, energy change.
Photosynthesis – chloroplast; CO₂ and H₂O → glucose and O₂; light energy is stored in chemical bonds. Respiration – mitochondria (and cytoplasm); glucose and O₂ → CO₂ and H₂O; energy is stored in ATP.
2
What was S. N. Winogradsky’s discovery and why is it important for biology?
In 1887 he discovered chemosynthesis: some bacteria make organic matter without sunlight by oxidising inorganic substances. This showed that autotrophy is not only photosynthesis and that life can exist without light.
3
For the DNA template strand TAC GGT CAA, write the mRNA and its tRNA anticodons.
mRNA: AUG CCA GUU; anticodons: UAC GGU CAA.
4
A protein has 200 amino acids. How many nucleotides does the mRNA region coding it have, not counting the stop codon? (Number only.)
600
5
Explain with an example why the universality of the genetic code matters for genetic engineering.
Because a gene of one species gives the same protein in the cell of another species: for example, the human insulin gene is read in bacteria, which then make insulin.