Cells Flashcards
Features of smooth endoplasmic reticulum?
No ribosomes, site of lipid synthesis, stores & releases calcium.
Features of rough endoplasmic reticulum?
Studded with ribosomes, site of protein synthesis
What are ribosomes for?
Translate mRNA into protein
What does the cell membrane do?
1) Regulate passage of substances
2) Detect chemical messenges
3) Link adjacent cells together
4) Anchor cells to extracellular matrix
What do microtubules do?
Give structure to the cell.
What happens in the mitochondria?
Oxidative phosphorylation
What happens in the matrix?
Kreb’s cycle
Features of nucleus?
Brain of cell, double nuclear membrane, house of DNA.
What is the outer and inner membrane of motochondria for?
Outer: Lipid synthesis & fatty acid metabolism
Inner: Respiratory chain, ATP production.
What is the intramembranous space of the mitochondria for?
Nucleotide phosphorylation (ADP to ATP)
Which cell can the golgi apparatus be easily seen in?
Plasma cells
Where is the golgi apparatus located?
Close to the nucleus
What are lysosomes?
Waste disposal system and site of breakdown for most molecules. They also break down debris from dead cells & bacteria and damaged cell organelles.
What are peroxisomes?
Small, membrane bound organelles containing enzymes that oxidise long chain fatty acids. They also produce hydrogen peroxide which can be used to destroy pathogens.
What is the cytoskeleton for?
Filamentous proteins which brace the internal structure of the cell. This is not visible in light microscopy
What is lipofuscin?
Membrane bound orange-brown pigment, common in heart and liver and is sign of wear and tear.
What is a lipid?
Non membrane bound vacuiles that appear as empty space in histology as they dissolve in processing, they are stored in adipocytes and liver.
What is glycogen?
CHO polymer in cytoplasm, usually only seen in electron microscopy.
What are macromolecules?
Simple molecules e.g. sugars, lipids and amino acids and can form large complex molecules.
What is the general formula of a carbohydrate?
Cn(H20)n
Glucose + galactose=
Lactose
Glucose + fructose=
Sucrose
Glucose + glucose=
Maltose
What is a monosaccharide?
Chain of carbons, hydroxy groups, one carbonyl group.
How are cyclized ring structures made?
By the reaction of the aldehyde or ketone group with a hydroxy group of the same molecule.
How does a glycosidic bond form?
The hydroxy group of a monosaccharide can react with an OH or NH to form a glycosidic bond.
How many monosaccharides are in a disaccharide?
2
How many monosaccharides are in a oligosaccharide?
3-12
How many monosaccharides in a polysaccharide?
10’s to 1000’s
What are features of the phospholipid bilayer?
Polar molecules (facing outside) allows so molecules in/ out the cell. (Simple diffusion)
Large molecules enter the cell via?
Transport proteins (facilitated diffusion)
What does the cell membrane contain?
Cholesterol, proteins, glycolipids/ glycoproteins
What are the 5 types of cell junctions?
Tight, adherens, demosome, gap junctions, hemidesmosome
What is the function of a tight junction?
Seals neighboring cells together in an epithelial sheet to prevent leakage of molecules between them.
What is the function os adherehs junction?
Joins an actin bundle in one cell to a similar bundle in a neighboring cell.
What is the function of a desmosome junction?
Joins intermediate filaments in one cell to those in another.
What is the function of a gap junction?
Allows the passage of small water-soluble ions and molecules.
What is the function of hemidesmosome junctions?
Anchors intermediate filament in a cell to basal lamina.
How many amino acids are there?
20
What is a polypeptide?
The bond between the amino acid and carboyx group
What is the structure of the cell membrane?
Double layer of lipid molecules containing embedded proteins. Phospholipids have polar regions that are orientated towards surface of the membrane as they are attracted to water in extracellular fluid. Its flexible but cant be stretched.
What are the 2 membrane proteins?
Integral: Cant be extracted and most are transmembrane which cross the lipid bilayer many times.
Peripheral: Located at membrane surface and associated with cytoskeleton elements.
What happens in the golgi apparatus?
Gathers simple molecules and makes them complex. Big molecules are they packaged in vesicles
