Basic Cell Structure Flashcards
What are the functions of the plasmalemma (plasma membrane)?
Selective permeability, transport of material along cell surface, endocytosis, exocytosis, intercellular adhesion, intercellular recognition, signal transduction
Name the direction of movement through the golgi
Cis –> trans
What shape is smooth ER on a scan?
Blebbed
What is a peroxisome?
Contain enzymes degrade long chain fatty acids. In liver/kidney detoxify alcohol, phenols, formaldehyde
What is the nuclear envelope?
phospholipid bilayer membrane which surrounds the genetic material and nucleolus
In which cells are the mitochondrial cristae tubular?
steroidogenic cells
What are the benefits of microvilli?
gives increased surface area but minimises an increase in volume
Why is brown fat brown?
high levels of mitochondria
Which structure of the cell is amphipathic?
the phospholipid bilayer (both hydrophilic and hydrophobic parts)
What is the glycocalyx made of? And where is it positioned?
oligosaccharide and polysaccharide side chains outside the plasma membrane
What is the role of intermediate filaments?
Form tough supporting meshwork in cytoplasm, also found beneath inner nuclear membrane forming nuclear lamina
Name the function of the smooth ER
LIPID production, storage, transport
Describe the structure of a mitochondria
2 membrane, inner membrane folds = cristae (site of oxidation of respiratory chain), matrix = space between folds
Name the function of rough ER
Protein synthesis. inter = between cisternae. Intra = inside cisternae
Where is smooth ER commonly found?
liver, mammary glands, ovaries, testis
Role of the golgi?
vesicles with proteins from rER go to golgi to be modified, concentrated and then bud off to be exported outside the cell or form a lysosome
What organelle is found is both prokaryotes and eukaryotes?
ribosomes
What is a lysosome and its enzymes?
Contains glycosidases, proteases and sulfatases that break substances into smaller molecules
What is special about mitochondrial DNA?
maternally inherited DNA, contain characteristically prokaryotic RNA
What is the function of the mitochondria?
powerhouse, ATP by oxidative phosphorylation
Where will actin filaments (microfilaments) be found?
Underlying plasma membrane, part of the muscle contractile unit
List cellular structural support in order of size
Actin 5-9nm, intermediate filament 10nm, microtubules 25nm
Describe microtubules and its function?
Hollow cylinders made of protein tubulin.
Rigidness so can support other structures in the cell, ability to generate movement: moving centrioles during mitosis, cilia and flagella
What is the difference between cytoplasm and cytosol?
Cytoplasm = everything inside the plasma membrane bar the nucleus: cytosol and the organelles
Cytosol = fluid surrounding the nucleus and the organelles = water, salts, macromolecules - 70% cell volume
What is the nucleolus?
Site of ribosome synthesis
What is a secondary lysosome?
A lysosome that has already fused with a bacteria and contains its residue
why is it good for eukaryotic cells to be compartmentalized?
so that reactions dont interfere with each other, many can occur
what word defines lipid production?
steriodogenesis
what is the difference between a lysosome and peroxisome on a TEM?
peroxisomes are darker
what is the limit of resolution?
the minimum distance at which 2 objects can be distinguished
