Life at Cellular Level Flashcards
Why are cells small?
Small cell keeps a large surface area to volume ratio - needed for easy absorption of substances
Do prokaryotes have mitochondria?
No
What is the difference between pluripotent cells and multipotent cells?
Multipotent - can differentiate into many cell types
Totipotent - can differentiate into every type of cell in the body.
Stem cells are usually categorized as multipotent (able to give rise to multiple cells within a lineage), pluripotent (able to give rise to all cell types in an adult) and totipotent (able to give rise to all embryonic and adult lineages).
Multipotent cells can develop into more than one cell type, but are more limited than pluripotent cells; adult stem cells and cord blood stem cells are considered multipotent.
What are the key differences between necrosis and apoptosis?
Necrosis - Days, groups of cells, damage to neighbouring cells, inflammation
Apoptosis - Hours, individual cells are induced to die, no damage to neighbouring cells, no inflammation
Describe the shape of mitochondrial DNA
Circular
What does the endoplasmic reticulum do?
Site of protein and glycolipid synthesis
Which proteins does the golgi apparatus add sugars to?
Membrane proteins
Lysosomal proteins
Secretory proteins
What is the word used to describe membrane lipids?
Amphipathic
A chemical compound containing both polar (water-soluble) and nonpolar (not water-soluble) portions in its structure.
What function do telomeres have?
They stabilise the ends of the chromosomes
What function do centromeres have?
They ensure distribution of chromosomes to daughter cells when the cell divides
What is splicing?
Removing introns during translation
What is the ribosome composed of?
Ribosomal RNA
What is responsible for autophagy?
The lysosome
What is the function of the cytoskeleton?
Holds organelles in place and moves them
Supports and maintains cell shape
What three structures comprise the cytoskeleton?
Microfilaments
Intermediate filaments
Microtubules
What is the structure of microfilaments?
Made up of actin protein strands - thin and contractile
What are microfilaments responsible for?
Provide structure
Cell cell anchoring
What is the structure of intermediate filaments?
Consists of fibrous proteins, organised in tough rope-like assemblages
What is the function of intermediate filaments?
Stabilise cell structure, prevents collisions within the cell
What is the structure of microtubules?
Thick, Long, hollow cylinders made from tubulin (a dimer composed of alpha and beta tubulin)
What is the function of microtubules?
Transport materials in cytoplasm
What is the peroxisome responsible for?
Oxidation of fatty acids
What type of atoms form the strongest bonds?
Light atoms
What are the two isomers of the c-c double bond?
Cis (meaning same)
Trans (meaning opposite)
What are the names given to the two forms of carbon?
Laevo (left handed)
Dextro (right handed)
What type of amino acids are proteins made from?
Left handed (laevo)
What is defined as comformation?
The precise arrangement of atoms in a molecule
What is the intermediate product between glucose and pyruvic acid, and what products does its formation produce?
Phosphoenolypyruvate
Makes 2 ATP each
Makes 1 NADH each
Is condenSation a Synthesis or degradation reaction, what does it always produce?
It is a synthesis reaction that produces water
What type of reaction occurs between the pentose sugar of one nucleotide and the phosphate of an adjacent nucleotide?
Dehydration reduction
What is the difference between a nucleoside and a nucleoTide ?
Nucleoside does not contain a phosphaTe group but nucleoTide does ;)