Atlas of plant and animal histology

Choose true or false. Each right answer scores 1, and each wrong answer scores -1. Not answered questions score 0.

1) One of the functions of cell membranes is to form ionic gradients that are used for ATP synthesis.

2) The structure of membranes is based on the physicochemical features of membrane lipids.

3) Carbohydrates linked to membrane proteins and lipids are found on the cytosolic surface of the plasma membrane.

4) All cellular membranes have the same amount of proteins and lipids.

5) Sphingolipids are the main lipid type of cell membranes.

6) Lipids influence the membrane fluidity.

7) Cholesterol is found in the inner leaflet of the plasma membrane but not in the external leaflet.

8) Lipids are evenly distributed in cell membranes because of the membrane fluidity.

9) Most functions of membranes are carried out by membrane proteins.

10) Transmembrane proteins are anchored to the plasma membrane by hydrophobic forces.

11) Peripheral proteins are linked to the surface of the ​membrane by chemical bonds.

12) Glycocalyx is the cloud of carbohydrates that covers the external surface of cells. These carbohydrates are linked to plasma membrane molecules.

13) Carbohydrates of the plasma membrane are chemically bound to proteins and lipids.

14) Membrane carbohydrates have no specific functions.

15) Membrane semipermeability is a membrane property that allows the lateral movement of lipids.

16) Oxygen and carbon dioxide may cross the plasma membrane without restrictions.

17) Water can freely cross the plasma membrane.

18) Lipid rafts make possible characteristic chemical environments that favor some chemical reactions and molecular interactions.

19) Membrane asymmetry means that there is a different molecular composition between both leaflets of the membrane.

20) Large membrane breakages (of about 0.2 µm) are sealed by the lipid properties.

21) Transmembrane proteins of the plasma membrane are mostly synthesized in the Golgi apparatus.

22) Transmembrane proteins of mitochondrial membranes are synthesized in the endoplasmic reticulum.

23) Cell membranes are continuously renewed.

24) Ion gradients can be generated thanks to the permeability properties of membranes.

25) Pumps are membrane proteins that form ion gradients by ATP hydrolysis.

26) Cotransport of molecules across membranes is carried out by proteins called co-transporters.

27) Chanels are transmembrane proteins that allow ions to cross membranes against concentration gradient.