Nucleus, Ribosomes, Lysosomes, Peroxisomes, Plasma membrane, Endocytosis, Transcription, Translation, Protein 3D-structures, Chemical forces, Ligand-receptor interactions and more.
,1. Characteristics of the Human cell
Human cells are typical eukaryotic cells, surrounded by a plasma membrane. In general, the
cells range from 1-100 m in size. Within tissue the cells are bound together by an
intracellular matrix filled with collagen.
1.1 All cell organelles and their properties.
For each organelle the following questions are answered below:
1. What is the function?
2. What is the structure?
3. Why is it needed?
4. What are typical proteins related to the organelle?
Nucleus (6 m)
What is the function?
The nucleus holds all of the genetic code of the cell, contained in DNA. It serves to protect
and regulate (via the Nuclear pores) the gene expression an DNA replication.
What is the structure?
Chromatin is a complex of proteins with DNA. The nuclear envelope is a protective layer
passable for water-soluble molecules/certain RNA strands/ribosome subunits. Nucleoplasm
is similar to cytoplasm. Nucleolus contains rDNA and it’s a ribosome creation site.
2
, Why is it needed?
The nucleus serves the important function of protecting DNA, the basis of the cell. It is
absolutely necessary for survival as it enables gene expression, cell division and repairs.
What are typical proteins?
• Chromatin: a complex of DNA and proteins.
• Nucleoporins: transport proteins with the structure of nuclear pores.
• Enzymes:
o Helicases – unwinds double stranded DNA
o Polymerases – create mRNA from DNA precursors
Nuclear Pores (0.2 m) and Nuclear Envelope
What is the function?
The nuclear envelope (NE) is a barrier layer that contains the nucleolus, chromatin and
nucleoplasm. It keeps the genetic material safe. The separation allows replication in the
nucleus to occur prior to nuclear division and to produce different types of RNA. A nuclear
pore (NP) is a miniscule opening through the NE. It regulates the import/export of
macromolecules such as proteins, mRNA, tRNA, ribosome subunits and viruses.
What is the structure?
See next page.
Why is it needed?
It protects the nucleolus (and genetic material) and regulates import/export.
What are typical proteins?
Nucleoporins and phospholipids.
Rough ER, smooth ER and Ribosomes (7 nm)
What is the function?
The rough ER has ribosomes attached to it; hence the name. It is adjacent to the nucleus
and is involved with production and modification of proteins. Proteins produced via the
rough ER have a specific destination
The smooth ER doesn’t have ribosomes attached to it. It is involved with the synthesis of
lipids and steroid hormones as well as detoxification.
Ribosomes consist of about 60% RNA and 40% protein. There are small and large ribosomal
subunits as well as free and membrane-bound ones. They are involved with translation.
3
Voordelen van het kopen van samenvattingen bij Stuvia op een rij:
Verzekerd van kwaliteit door reviews
Stuvia-klanten hebben meer dan 700.000 samenvattingen beoordeeld. Zo weet je zeker dat je de beste documenten koopt!
Snel en makkelijk kopen
Je betaalt supersnel en eenmalig met iDeal, creditcard of Stuvia-tegoed voor de samenvatting. Zonder lidmaatschap.
Focus op de essentie
Samenvattingen worden geschreven voor en door anderen. Daarom zijn de samenvattingen altijd betrouwbaar en actueel. Zo kom je snel tot de kern!
Veelgestelde vragen
Wat krijg ik als ik dit document koop?
Je krijgt een PDF, die direct beschikbaar is na je aankoop. Het gekochte document is altijd, overal en oneindig toegankelijk via je profiel.
Tevredenheidsgarantie: hoe werkt dat?
Onze tevredenheidsgarantie zorgt ervoor dat je altijd een studiedocument vindt dat goed bij je past. Je vult een formulier in en onze klantenservice regelt de rest.
Van wie koop ik deze samenvatting?
Stuvia is een marktplaats, je koop dit document dus niet van ons, maar van verkoper jimzinkenjim. Stuvia faciliteert de betaling aan de verkoper.
Zit ik meteen vast aan een abonnement?
Nee, je koopt alleen deze samenvatting voor €6,99. Je zit daarna nergens aan vast.
