Organelles

What is phagocytosis?

How do chloroplasts divide?

Outline phagocytosis.

Why is it important for the thylakoid membranes to be very fluid as a result of their high concentration of unsaturated fatty acids?

Why do thylakoid membranes adhere to form granal stacks?

What is pinocytosis generally carried out by?

What is chlorophyll?

Name a more efficient process than pinocytosis and outline why it is more efficient.

Name 3 substances endocytosed by a receptor-mediated mechanism.

What is an endosome?

What are lysosomes?

How do lysosomal proteins avoid digestion by proteases?

What is autophagy?

List some processes that mitochrondria are involved in.

Why can mitochrondria synthesis their own proteins?

Describe the structure of a mitochondrion.

Why is the composition of the intramembranous space of the mitochondria similar to the cytosol?

What is the inner mitochondrial membrane impermeable to?

Where does electron transport and proton pumping occur?

Where are high concentrations of mitochondria found?

What stain can be used to differentiate mitochondria?

Can the nucleus be resolved by light microscopy? Which is the best stain to use in a metaphase spread?

What is heterochromatin?

What is euchromatin?

What is chromatin?

Why is the nucleolus extremely electron dense?

What is the perinuclear space?

What sized molecules can passively diffuse through nuclear pore complexes?

What signals for a molecule (e.g. mRNAs, RNA polymerase etc) to be removed from or retained in the nucleus?

What is a chromosome territory?

What is a lampbrush chromosome?

What are lamin proteins?

What are the 3 components of the nucleus, named after their staining density in electron microscopy?

What is the main function of the nucleolus?

What are casal bodies?

What are ribosomes?

What determines how often a protein is translated and demonstrates how active a gene is?

In Svedberg units, what size is a prokaryotic ribosome and what sizes are its subunits?

What are Svedberg units and why can't they be added together?

What size, in Svedberg units, are eukaryotic ribosomes and their subunits?

List some conformations that RNA may be visible as.

How can one break a ribosome down into its subunits?

In which cells is there a regulated exocytosis pathway?

What are chloroplasts?

Why does exocytosis not increase the size of the plasma membrane and deplete organelle membranes?

How does the trans Golgi network differentiate between secretory and constitutive proteins?

Give examples of what may be secreted from secretory vesicles.

How big are chloroplasts?

Give examples of extracellular signals that may cause vesicles to fuse with the plasma membrane and release their contents into the cell exterior.

What is continuous exocytosis significant in?

What are the 3 membrane systems of the chloroplast?

What is endocytosis?

What happens to endocytic material?

What is pinocytosis?

Where does the formation of disulphide bonds occur and why are they important?

Glycosylation occurs in the ER lumen by enzymes not present in the cytostol. List some functions of the covalent attachment of short oligosaccharides to proteins.

What is the basic process of glycosylation before the modification of the oligosaccharides in the ER and Golgi bodies to diversify them?

What are chaperone proteins?

What is the unfolded protein response and how may apoptosis occur?

What is the Golgi apparatus and where is it located?

How do soluble proteins and membrane travel through the Golgi cisternae?

How are proteins/membrane segments modified in the correct sequence?

Which two protein components are involved in guiding the ER signal sequence to the ER membrane, and how does this work?

Which terminus is the signal sequence usually located at?

What are the two functions of a signal sequence?

What causes the translocation of a polypeptide across the endoplasmic reticulum membrane to stop?

How does a simple transmembrane protein stop translocation fully through the ER membrane?

What are the two major vesicular transport pathways between membrane-enclosed compartments?

Why are there different types of transport vesicle?

What are cargo receptors and coat proteins?

What are Rab proteins?

How does docking of a vesicle occur?

How does fusion of a vesicle to a target occur?

In eukaryotic cells, what is the endoplasmic reticulum continuous with?

What is the function of the rough endoplasmic reticulum?

What is the function of the smooth endoplasmic reticulum?

What is the function of the Golgi apparatus?

What governs transport in a cell?

Which proteins are not synthesised by cytoplasmic ribosomes?

What do the cytosolic and membrane-bound ribosomes each tend to synthesise?

What is a sorting signal?

In which structures do proteins usually unfold, rather than remaining globular, in order to pass through?

What are the two types of protein transferred from the cytosol to the endoplasmic reticulum?

What is the need for the separate rough region of the endoplasmic reticulum?