Cells & Viruses Flashcards

Question

Describe the structure of the Golgi apparatus

Answer 1

A stack of membrane bound sacs ( called cisternae) Formining face has vesicles from the rough ER joining it Mature face has vesicles pinching off

Answer 2

Polypeptides are combined ( to form quaternary proteins ) or modified ( e.g glycoproteins ) Finished proteins are packaged into vesicles either for secretion by exocytosis or delivery within the cell

Answer 3

Vesicles produced by the Golgi apparatus that contain hydrolytic enzymes

Answer 4

They combine with membrane-bound degenerate organelles ( or ingested particles ) This forms secondary lysosomes Hydrolytic enzymes digest the contents

Answer 5

Sausage shaped surrounded by a double membrane, inner membrane is folded into cristae It has a fluid-filled matrix

Answer 6

Synthesis of ATP by aerobic respiration

Answer 7

Ovoid, surrounded by a double membrane, has a system of lamellae with thylakoids stacked into grana, also contain lipid droplets and starch grains

Answer 8

Site of photosynthesis Chlorophyll molecules are attached to the lamellae

Answer 9

Large permanent structure, membrane of the sap vacuole in plant cells is called the tonoplast

Answer 10

Storage of water and ions

Answer 11

Tubular, formed from the protein Tubulin, Occur within centrioles and throughout the cytoplasm, animal and fungal cells both contain a pair of centrioles. They occur as nine triplets of microtubules in a circular arrangement

Answer 12

Centrioles form the spindle fibres during cell division, microtubules also form part of the cytoskeleton and allow movement of cell organelles

Answer 13

Finger-like folds of the cell surface membrane

Answer 14

Increases the surface area for absorption of molecules and ions

Answer 15

Strands of cytoplasm between neighbouring plant cells that pass through pores in the walls

Answer 16

Allow the transport of materials between adjacent plant cells

Answer 17

They are so small they are measured in manometers (10nm-300nm)

Answer 18

Encased in a protein coat that surrounds nucleic acid (the nucleic acid can be DNA or RNA)

Answer 19

 Bacteriophages or phages have a DNA core and parasitise bacteria.  Inside their hosts (bacteria), the viral DNA codes for new proteins to make the capsid  The DNA replicates to make lots of new copies that are packaged within these protein coats, forming new viruses.  The bacterial cell ruptures releasing lots of new viruses to continue the cycle. The bacterial cell is destroyed in the process.

Answer 20

 Retroviruses have an RNA core  This RNA is encased in protein coat and surrounded by a lipid bilayer containing glycoprotein.  The RNA is delivered into the host cell by the retrovirus, along with the enzyme reverse transcriptase.  Reverse transcriptase catalyses the formation of DNA from this RNA.  This DNA is used to synthesise new viruses, by making protein coats and viral RNA. Normally, DNA is used to synthesise RNA, however in retroviruses the reverse happens and the RNA is used to make DNA.

Answer 21

because it invades a particular lymphocyte called a helper T- cell. Helper T cells are important in protecting against disease. The more cells that are invaded the less effective the immune system, until it becomes critically compromised, and AIDS may develop.

Answer 22

 The earliest formed organisms  They have no “true” nucleus.  Cell or organism’s DNA is not organised into chromosomes and is not surrounded by a nuclear membrane  They possess naked, circular DNA, small ribosomes, possibly plasmids and a cell wall made of peptidoglycan or murein.  There are no membrane bound organelles.  Examples include Bacteria and blue green algae

Answer 23

 A cell wall made of chitin  Often contain a vacuole  Glycogen as a carbohydrate store  Lysosomes  Often multinucleate (many nuclei within each cell)  They do NOT photosynthesise and do NOT have chloroplasts  Many fungal cell appear long and have elongated threads of hyphae that spread through the substrate