Ch 3: Cell Membrane Flashcards
What is cell theory?
It’s the concept that all organisms are made up of cells.
What is cell theory?
Cell theory is the concept that all organisms are made up of cells.
What are the main components of the cell membrane?
Theres phospholipids (lipids) and proteins.
In phospholipids, what are the tails and heads made of?
The tails are made of hydrophobic fatty acids while the heads are made of hydrophilic phosphorous.
What is the function of cholesterol in the cell membrane + how does temperature affect phospholipid fluidity?
The higher the cholesterol content the lower the fluidity of the lipids, meaning it reduces fluidity, at higher temperatures the fluidity increases while at lower it decreases.
What is a a solvit vs a solvent?
- Solvit: substance that dissolves in liquid.
- Solvent: substances that dissolves the solvit.
What are hypotonic, hypertonic and isotonic solutions?
- Hypotonic: dilute solution, there is more solvent than solvit.
- Isotonic: equal solvit to solvent amount.
- Hypertonic: concentrated solution, more solvit than solvent.
What is pinocytosis?
It is endocytosis of liquids.
How many genes are in the nucleus of a human cell?
There are about 30.000
What type of mature cell does not divide?
Mature red blood cells.
What is the composition of nuclear material?
Histones (proteins)
DNA, double helix made of nucleotides linked together through covalent bonds.
How many amino acids are there in total?
20 aa
What are rna characteristics?
Carries instructions from nuclear DNA to to cytoplasm.
Has ribose + uracil.
What are the 4 types of rna?
Ribosomal rna: present in ribosome
Transfer rna: present freely in cytoplasm, carries amino acids to ribosomes to be translated.
Messenger rna: receives genetic code from dna, carries it to cytoplasm, aka from DNA to mRNA.
Regulatory rna: regulates gene expression + protein synthesis through methods still unknown.
Describe transcription.
It is in the nucleus, RNA polymerase goes along the template strand, ignoring the dormant strand, making an mRNA strand complimentary to it, this strand stop synthesis at the terminal signal receival, then mRNA goes through the nuclear pore into the cytoplasm towards the ribosome.
