Lecture 1 – cell biology (cells)
Cells come in different shapes and sizes
- They have different aspects
o They are membrane-enclosed unit of life
o Have metabolism = each cell has a different way it metabolizes
o Growth and division
o Response to environmental signals, internal and external communication
Cell biology has different topics. The questions that are always asked are
- What happens? In and outside a cell
- Which factors are involved?
- Why does it happen? – the cause and consequence
- Where does it happen in the cell?
- Can we modify/ manipulate cellular processes?
Cell biology relates to many other fields = so it is interdisciplinary
- Bio-medicine = to understand why certain diseases occur etc.
DNA = genetic material
Proteins = the workhorses
Metabolites = molecules produced or altered by cell
! there are alot of feedback moments in between all of these
which is very important !
,Different cell types
1. Prokaryotic cell
o Small: 1 – 5 µm (it is good to know the size of
things to know which technique is best to use
in research)
o Typically single cells
o No internal membrane compartments
o Very flexible metabolism
2. Eukaryotic cell
o Larger than the prokaryotic cell: 20 – 50 µm
o Many are milty-cellular
o Has membrane-enclosed compartments
Nucleus
• The place for DNA synthsis and storage of the DNA
• RNA synthesis also happens = specifically in the nucleolus
o The nucleolus
1. is the site of RNA and ribosome synthesis
2. It is involved in protein quality control
• Chaperones will fold the denatured proteins
again when misfolded
Frottin et al. 2019
- They stained the nucleolus of a certain area. They used
markers for this
- A protein is then put into the nucleolus labeled with
GFP (a dye)
- A heat system destabalizes the protein
- This destabalized protein moves to the previously
marked area in the nucleolus to be refolded
• The nucleus is surrounded by a phospholipid membrane
• The membrane has nuclear pores for transort between the cytosol
and the nucleus
, Endoplasmatic reticulum (ER)
• Large part of the cell
• For moving/ modification/ transport/ sorting of proteins
• Also closely connected to protein synthesis
o Specifically the proteins that enter the cell = the first station
they encounter is the ER
• Has many functions
o Improtant role in division of mitochondria
1. The ER mediates this process
2. It forms a clamp around the mitochondria at the
place it needs to split
Glycosylation = post translational
modification – different types of glycans
Golgi apparatus are covalently attached to proteins
• Membrane system
• On the route, after the ER, the proteins encounter the golgi
apparatus. It mofidies the membrane proteins
o In particular glycosylation happens of the proteins
• Sorting and transport of proteins happens here as well
o The transport happens from and within the golgi by
transport vessicles
o The golgi apparatus has two sides = Cis- and trans- side
Mitochondria
• It produces ATP = energy metabolism
• Fatty acid oxidation takes place there
• Functions = ATP prduction and plays a role in the cytric acid cyle
Lysosome
• Very small: several 100 nm
• Contains hydolytic enzymes = break down large molecules into
smaller ones
• Functions
o Degredation and signaling processes
1.> Involved in autophagy (settembre et al, 2013) = eats
up proteins/other stuff to degrade it
o Secretion
Transport vessicles
• They are used for transport between compartments
• Are membrane enclosed vessicles
• Smaller than other organelles
• Crucial for transport material between two comparments in a cell
• Closely related to the ER and golgi
, Cytoskeleton
• Functions
o It is structuring the cell
o Important for movement of the cell
o Transport in the cell
• Fillaments = are protein based structures that all have the functions
that are stated above
o Thick = microtubule
o Thin = Actin
o Intermediate = keratine
Chloroplast
• Involved in photosynthesis = energy from the sun --> ATP
Cytosol
• Water based gel
• Contains a lot of molecules = macro and micro
o Which means that the cytosol is very crowded
1.> Consequence = metabolites do not have a lot of
space left
2.> The metabolites are very close to eachother so the
effective concentrations and reaction rates are
higher
• Many metabolic steps happen in the
cytosol
Cells come in different shapes and sizes
- They have different aspects
o They are membrane-enclosed unit of life
o Have metabolism = each cell has a different way it metabolizes
o Growth and division
o Response to environmental signals, internal and external communication
Cell biology has different topics. The questions that are always asked are
- What happens? In and outside a cell
- Which factors are involved?
- Why does it happen? – the cause and consequence
- Where does it happen in the cell?
- Can we modify/ manipulate cellular processes?
Cell biology relates to many other fields = so it is interdisciplinary
- Bio-medicine = to understand why certain diseases occur etc.
DNA = genetic material
Proteins = the workhorses
Metabolites = molecules produced or altered by cell
! there are alot of feedback moments in between all of these
which is very important !
,Different cell types
1. Prokaryotic cell
o Small: 1 – 5 µm (it is good to know the size of
things to know which technique is best to use
in research)
o Typically single cells
o No internal membrane compartments
o Very flexible metabolism
2. Eukaryotic cell
o Larger than the prokaryotic cell: 20 – 50 µm
o Many are milty-cellular
o Has membrane-enclosed compartments
Nucleus
• The place for DNA synthsis and storage of the DNA
• RNA synthesis also happens = specifically in the nucleolus
o The nucleolus
1. is the site of RNA and ribosome synthesis
2. It is involved in protein quality control
• Chaperones will fold the denatured proteins
again when misfolded
Frottin et al. 2019
- They stained the nucleolus of a certain area. They used
markers for this
- A protein is then put into the nucleolus labeled with
GFP (a dye)
- A heat system destabalizes the protein
- This destabalized protein moves to the previously
marked area in the nucleolus to be refolded
• The nucleus is surrounded by a phospholipid membrane
• The membrane has nuclear pores for transort between the cytosol
and the nucleus
, Endoplasmatic reticulum (ER)
• Large part of the cell
• For moving/ modification/ transport/ sorting of proteins
• Also closely connected to protein synthesis
o Specifically the proteins that enter the cell = the first station
they encounter is the ER
• Has many functions
o Improtant role in division of mitochondria
1. The ER mediates this process
2. It forms a clamp around the mitochondria at the
place it needs to split
Glycosylation = post translational
modification – different types of glycans
Golgi apparatus are covalently attached to proteins
• Membrane system
• On the route, after the ER, the proteins encounter the golgi
apparatus. It mofidies the membrane proteins
o In particular glycosylation happens of the proteins
• Sorting and transport of proteins happens here as well
o The transport happens from and within the golgi by
transport vessicles
o The golgi apparatus has two sides = Cis- and trans- side
Mitochondria
• It produces ATP = energy metabolism
• Fatty acid oxidation takes place there
• Functions = ATP prduction and plays a role in the cytric acid cyle
Lysosome
• Very small: several 100 nm
• Contains hydolytic enzymes = break down large molecules into
smaller ones
• Functions
o Degredation and signaling processes
1.> Involved in autophagy (settembre et al, 2013) = eats
up proteins/other stuff to degrade it
o Secretion
Transport vessicles
• They are used for transport between compartments
• Are membrane enclosed vessicles
• Smaller than other organelles
• Crucial for transport material between two comparments in a cell
• Closely related to the ER and golgi
, Cytoskeleton
• Functions
o It is structuring the cell
o Important for movement of the cell
o Transport in the cell
• Fillaments = are protein based structures that all have the functions
that are stated above
o Thick = microtubule
o Thin = Actin
o Intermediate = keratine
Chloroplast
• Involved in photosynthesis = energy from the sun --> ATP
Cytosol
• Water based gel
• Contains a lot of molecules = macro and micro
o Which means that the cytosol is very crowded
1.> Consequence = metabolites do not have a lot of
space left
2.> The metabolites are very close to eachother so the
effective concentrations and reaction rates are
higher
• Many metabolic steps happen in the
cytosol
