L10- Into to cells

Question 1

what is the nucleolus?

Answer 1

a mass of densely stained granules and fibres associated with chromatin

Question 2

what is the role of the endoplasmic reticulum?

Answer 2

an extensive network of membranous tubles and sacs

Question 3

what is the role of the RER?

Answer 3

has ribosomes, it secretes cells in vast amounts like B-cells

Question 4

what is the role of the SER?

Answer 4

no ribosomes, contains enzymes for synthesis of lipids and hormones. stores Ca2+

Question 5

what is the role of the golgi apparatus?

Answer 5

• after leaving the ER trnasprt vesciles travel to the golgi where they are stored and further modified.
• contains enzymes for protein modification.

Question 6

what is the role of the lysosomes?

Answer 6

membrane bound vesicles produced by golgi apparatus?, they contain hydrolytic enzymes

Question 7

what is the role of the peroxisome?

Answer 7

they contain enzymes fr metablic reaction, contain oxidative enzymes, produce H2O2 as by product

Question 8

what is the endosymbotic theory?

Answer 8

eukaryotes evolved from the engulfment of prokaryotic cells. certain organelles mitchondria and chloroplast contain DNA that is similar to prokaryotic organisation.

2. Mitochondria and chloroplasts contain their own ribosomes (70 S).
3. ribosomal (rRNA) sequencing show chloroplasts and mitochondria are phylogenetically related to Eubacteria.
4. Many antibiotics such as streptomycin inhibit mitochondrial and chloroplast function.
5. Amoeba infected with bacteria can become dependent on them.