1.2 Ultrastructure of cells Flashcards
What are prokaryotic cells?
It is a cell with…
-no nucleus
-no organelles
-no compartmentalisation
What are eukaryotic cells?
A cell that contains a nucleus.
What is the structure and function of ribosomes?
-found in pro&eukaryotes
S: have two subunits made of RNA and protein
F: synthesize polypeptides (proteins) in a process called translation.
What is the structure and function of the cytoskeleton?
-found in pro&eukaryotes
S: scaffolding in the cytoplasm.
F: provides internal structure and helps intracellular transport.
What is the structure and function of the plasma membrane?
-found in pro&eukaryotes
S: phospholipid bilayer with proteins
F: semi-permeable—>selective barrier surrounding the cell
What is the structure and function of a nucleus?
S: double membrane, spherical w/ pores
F: stores chromosomes which are made of DNA.
What is the structure and function of a nucleolus?
S: found in the nucleus, no membrane, is granular, and dark
F: assembles ribosomes
What is the structure and function of the rough ER?
S: ribosomes attached to cisternae (folds)
F: synthesizes proteins
What is the structure and function of the smooth ER?
S: enzymes attached to its cisternae (folds)
F: synthesizes lipids like phospholipids and cholesterol
What is the structure and function of the golgi apparatus?
S: vesicles and membranes near the plasma membrane
F: sorts, stores, modification, exports secretory products
What is the structure and function of the mitochondrion?
S: double membrane, inner membrane folded
F: site of aerobic respiration, ATP production
What is the structure and function of the chloroplast?
plant cells only
S: double membrane with discs
F: site of photosynthesis
What is the structure and function of the vacuole?
plant cells only
S: large, central, fluid filled, 1 membrane
F: maintains hydrostatic (fluid) pressure
What is the structure and function of the cell wall?
plant cells only
S: external cellulose cover
F: support and strength, prevents excess water uptake
What is the structure and function of the lysosome?
animal cells only
S: sacs filled with hydrolysis enzymes
F: breakdown/hydrolysis of macromolecules
What inferences can we make about the multitude of a certain organelle?
For example
-many mitochondria = energy consuming processes –> neurons/muscle cells
-extensive ER networks = secretory activity –> plasma/exocrine gland cells
What’s the difference between a light microscope and an electron microscope?
Electron microscopes have a higher resolution and range of magnification, but cannot display in natural colors.
What is the difference between the cell wall and the plasma membrane?
The cell well is made of cellulose surrounding a plant cell. A plasma membrane is found in both plant and animal cells.
State one advantage a cell gains from being compartmentalized and having organelles.
Different chemical process can occur simultaneously in different parts of the cell.
