The cell

Question 1

Cellular membrane (functions)

Answer 1

diffusion barrier –> separation fo substances

• protection
• material & excitation transport
• growth
• mechanical connections between cells

Question 2

Cell membrane

Answer 2

• double lipid membrane

- hydrophilic (polar) and hydrophobic (unpolar) ends

Question 3

Proteins

Answer 3

primary structure: amino acids

Question 4

Protein structure

Answer 4

1) primary structure: sequence of amino acids within protein
2) secondary structure: indicates spatial arrangement of chain
3) tertiary structure: indicates spatial arrangement by further intramolecular interactions
4) Quaternary structure: superordinate structure of several protein units that form a protein complex

Question 5

Ion Channels

Answer 5

• Selectivity filter –> pores
• creating energetically stabilized positions for certain ion in the filter –> facilitation dehydration and thus the passage through the pore

Question 6

Action Potential - phases

Answer 6

1) resting potential
2) stimulus
3) depolarisation
4) repolarisation
5) hyperpolarisation
6) resting potential

Question 7

Signal propagation via synapses

Answer 7

• electrical synapse
  
  • no delay
  • bi-directional
  • gap junctions
• chemical synapse
  
  • approx. 1ms delay
  • uni-directional

Question 8

What is an eukaryote?

What is an prokaryote?

Answer 8

Euokaryote: cellular organism that has a nucleus enclosed within a nuclear envelope

Prokaryote: cellular organism that lacks an envelope-enclosed nucleus (e.g. bacteria)