Cell structure exam-style questions

Exam-style questions from Oxford revision guide

Name two components in plant cells that are not present in animal cells

Cellulose cell wall, chloroplasts, permanent vacuole

The cytoskeleton in cells is made up of microtubules and microfilaments. Outline the different roles of the cytoskeleton with examples

-provide support / strength to cells

-change cell shape, for example cytokinesis / phagocytosis / pinocytosis

-allow cell to move- e.g. flagella to help sperm cells move towards the egg, move vesicles within cells, separate chromosomes / sister chromatids during cell division

The digestion of starch starts in the mouth, where salivary glands produce amylase. Outline how different organelles within a salivary gland cell produce and release amylase out of the cell.

-the nucleus contains genes / codes for protein

-transcription occurs to produce mRNA

-protein synthesis / translation occurs in ribosomes

-Golgi body modifies / packages proteins

-transport vesicles transport proteins between organelles

-cytoskeleton moves vesicles between organelles or within the cell to the plasma membrane

-vesicles fuse with plasma membrane releasing amylase by exocytosis

Describe similarities and differences between protein synthesis in prokaryotic and eukaryotic cells

Similarities- transcription occurs to produce mRNA, translation occurs to produce proteins, ribosomes are involved in translation

Differences- in prokaryotes transcription occurs in the cytoplasm and in eukaryotes it occurs in the nucleus, in prokaryotes mRNA doesn’t travel but in eukaryotes it leaves the nucleus through the nuclear pore, in prokaryotes free ribosomes are involved but in eukaryotes the ribosomes can be on the rough ER

Describe how DNA is packaged within the nucleus in eukaryotic cells

Arranged into chromosomes and wrapped around histones

State a difference between the structure of bacterial DNA and animal chromosomes

Bacterial DNA is circular, animal DNA is linear, bacterial DNA does not have histones

Primary protein structure

Sequence of amino acids, peptide bonds involved

Secondary protein structure

Hydrogen bonds involved, alpha helices and beta pleated sheets formed

Tertiary protein structure

Disulphide bonds formed, hydrogen bonds involved, alpha helices and beta pleated sheets formed

Quaternary protein structure

-disulphide bonds formed, bonding with other subunits, hydrogen bonds involved