L4: Introduction To Human Cells Flashcards
What are the 2 classification of cells?
- Prokaryotes
- Eukaryotes
What are prokaryotes?
- single celled organisms without a nucleus
E.g/ eubacteria, arachaebacteria, cyanobacteria
What are eukaryotes?
- Single or multicellular organisms with a membrane bound nucleus
E.g/ plant and animal cells
What is the variety of human cells like?
- all cells have same genetic code
- all cells have similar internal strcutures but vastly different functions
What does pluripotent mean?
The cell can differentiate into many different cells
Give examples for cells that pluripotent stem cells can differentiate into
- pancreatic islet cells
- heart muscle
- blood cells
- nerve cells
- bone marrow cells
What component can the cell structure be separated into?
- nucleus
- cytoplasm (cytosol, inclusions, organelles, protein fibres)
- cell membrane
Examples of inclusions
- lipids
- glycogen
- ribosomes
Examples of organelles
- endoplasmic reticulum (smooth and rough)
- golgi apparatus
- mitochondria
- lysosomes
- peroxisomes
Examples of protein fibres
- cytoskeleton
- centrioles
- cilia
- flagella
Order of microscopic observation of cells (biggest to smallest) (7)
- typical human cells
- mitochondrion
- lysosome
- ribosome
- plasma membrane
- protein molecule
- hydrogen atom
What’s the difference in cytoplasm and cytosol?
Cytoplasm: everything in the cell except the nucleus
Cytosol: also excludes other organelles
What are the different classes of biological molecules?
- nucleic acids (DNA, RNA, Nucleotides)
- protein (a/a, polypeptides)
- lipids (FA, triglycerides, steroids)
- carbohydrates (mono/di/polysaccharides)
What is central dogma of cell biology?
The process by which the instructions in DNA are converted into a fuctional product
What is the function of the nucleus? + extra info
- storage and transmission of genetic info to the next gen of cells
- DNA is wound up around histones = chromatin
- Chromosomes are chromatin threads condensed
What are some of the nuclear structures?
- nuclear envelope
- nucleolus
- nuclear pores
- chromatin
(+ nucleoplasm)
Features of the nuclear envelope
- composed of 2 membranes
- openings called nuclear pores
= mRNA transcribed from DNA moves out through them
= proteins that modulate gene expression in DNA move in through them
What are the types of endosplasmic reticulum?
- Rough ER
- Smooth ER
What is the RER?
- double membrane with ribosomes bound to it
- involved in translation, packaging protein to send to the GA
What is the SER? (3)
- site where certain lipid molecules are synthesized
- plays role in detoxification of certain hydrophobic
- stores and releases calcium ions
What are ribosomes?
- the site of protein synthesis
(From a/a using genetic info from mRNA
Protein are synthesised
- on free ribosomes and released into the cytosol
- ribosomes on the RER
What is the golgi apparatus? (2)
- series of closely apposed, flattenes membranous sacs
- proteins pass, get modified, sorted and travel to various cell locations
What are secretory vesicles?
Vesicles containing proteins secreted from the GA
What is the mitochondria?
- organelle that participates in chem processes that transfer energy from chem bonds of nutrient molecules to ATP molecules
- most of the energy used by the cells is from ATP by aerobic respiration
What are lysosomes?
- spherical organelles surrounded by single membrane
- fluid within is acidic and contains digestive enzymes
- digesting food, organelles, cells
What are peroxisomes? (2)
- dense oval bodies enclosed by a single membrane
- consumes molecular O, removes H from lipids, alcohol, and potentially toxic ingested substances
What are endosomes/vesicles? (3)
- vesicles pinch off the plasma membrane travel to and fuse to endosomes
- endosomes can pinch vesicles off that return to the plasma membrane
- endosomes are involved in sorting. Modifying and directing vesicular traffic
What are types of cytoskeletons?
- actin filament (7nm, G-actin)
- intermediate filament (10nm, several proteins)
= microtubule (25nm, tubulin)
What is cilia?
Slender protuberances that project from the much larger cell body
What is flagella?
Lash-like appendage that protrudes from the cell body
