Cells Flashcards
Define the term “eukaryotic cell”. (F)
Cell with a true nucleus and other membrane-bound organelles.
Outline the structure of the nucleus. (F)
- contains DNA associated with histone proteins
- surrounded by nuclear envelope
- has a nucleolus
Outline the structure of the nucleolus. (F)
- area within nucleus
- made of proteins and RNA
Outline the structure of the nuclear envelope. (F)
- double membrane
- nuclear pores
Outline the structure of the rough endoplasmic reticulum (RER). (F)
- network of membranes enclosing flattened sacs called cisternae
- ribosomes
Outline the structure of the smooth endoplasmic reticulum (SER). (F)
- network of membranes enclosing flattened sacs called cisternae
Outline the structure of the Golgi apparatus. (F)
- compact
- cisternae
- no ribosomes
Outline the structure of ribosomes in eukaryotic cells. (F)
- made of a large and small subunit
- made from rRNA
- 80s
Outline the structure of the mitochondria. (F)
- highly folded double membrane to form cristae
- interior fluid called matrix
- enzymes used in aerobic respiration
- some DNA
Outline the structure of lysosomes. (F)
- vesicle
- contains digestive (hydrolytic) enzymes
Outline the structure of chloroplasts. (F)
- double membrane
- enclosed fluid called stroma
- internal membrane network form flattened sacs called thylakoids
- several thylakoids stacked together called granum (pl. grana) which are joined by lamellae
- grana contain chlorophyll pigments
- starch grains
Outline the structure of the plasma membrane in eukaryotic cells. (F)
Phospholipid bilayer
Outline the structure of the centrioles. (F)
- microtubules
- centrosome formed from two associated centrioles
Outline the structure of the cell wall in eukaryotic cells. (F)
- made from cellulose
- freely permeable
Outline the structure of flagella in eukaryotic cells. (F)
- microtubules
- 9 + 2 formation
Outline the structure of the cilia. (F)
- microtubules
- 9 + 2 formation
State 3 similarities between a typical plant and animal cell.
- both have mitochondria
- both have a nucleus
- both have a plasma membrane
- etc.
Describe how different organelles and molecules are involved in the process of protein production and trafficking in a cell. (F)
Nucleus: produces mRNA that codes for protein
Ribosome: synthesises protein
RER: packages protein in vesicles in cisternae
Cytoskeleton: transports vesicles
Golgi apparatus: structurally modifies proteins and packages into secretory vesicles
Plasma membrane: fuses with vesicles to release contents by exocytosis
Outline the structure of the 3 components of the cytoskeleton. (F)
Microfilaments:
- contractile fibres
- formed from actin (protein)
Microtubules:
- formed from tubulin (protein)
- scaffold-like structure
- tubes
Intermediate fibres:
- fibrous
Describe the functions of the cytoskeleton in a cell. (F)
- shape and stability of cell
- hold organelles in place
- controls cell movement
- controls organelle movement
Describe the importance of the cytoskeleton in movements of chromosomes, cilia, flagella and vesicles.
- spindle fibres are made of microtubules, which segregate chromosomes in cell division
- microtubules make up cilia and flagella and allow them to contract and move
- microtubules form a scaffold-like structure that acts as tracks for vesicle movement in cells
Define the term “prokaryotic cell”. (F)
cell with no true nucleus or membrane-bound organelles
List examples of prokaryotic cells.
- staphylococcus
- steptococcus
Outline the structure of the cell wall in prokaryotic cells. (F)
- made from peptidoglycan
- freely permeable