Topic 8: Cell Physiology 2 - Basic Cell Processes Flashcards
What are cells?
- living building blocks of the body
What is metabolism?
chemical processes in the body performed by cells
What is anabolism?
building molecules
What is catabolism?
- breakdown of molecules
What are the 3 steps in protein synthesis?
- DNA transcription
- mRNA translation
- After translation
What can proteins be?
- enzymes, structural, etc.
What occurs in DNA transcription? (3)
- DNA to mRNA
1. DNA uncoils at the site of gene to expose gene base sequence
2. RNA strand is formed. using code on DNA template to ass complementary RNA nucleotides
What occurs in mRNA translation? (4)
- mRNA to proteins
1. mRNA associates with ribosomes
2. tRNA with attached specific aa and anticodon binds to matching RNA
3. Peptide bond is formed to attach aa to growing peptide chain
What is a codon? (2)
3 bases on mRNA (base triplet)
- each codon codes for 1 aa, but aa can have more than one codon
Give a summary from transcription to protein using sequence of bases of DNA
- sequence of DNA bases determines mRNA sequence. which determines aa sequence for protein
What occurs in the after translation phase? (2)
- proteins produced on free ribosomes are released into cytosol or go to the nucleus or mitochondria
- proteins produced by ribosomes on RER are released into ER lumen
What happens after proteins are released into the ER? (3)
- modified by adding sugars (polypeptides)
- Transferred to golgi complex in vesicles
- Golgi further modifies proteins
What does the golgi do to proteins? (3)
- carb changes/additions, which acts as an address to send them to the right destination
- lipid additions
- packages modified proteins in vesicles and sends to destination (cell membrane, secretion, lysosomes)
What are lysosomes?
- membrane-bound organelles containing digestive enzymes (acid environment)
What are the functions and characteristics of enzymes? (5)
- names usually end in -ase
- increase reaction rates
- not used up in rxn
- very sensitive to pH, temp
- very specific
What is ATP? (2)
- adenosine triphosphate
- adenine + ribose (adenosine) and 3 phosphates
Where is energy stored in ATP?
- in phosphate bonds (COVALENT)
What is energy produced from ATP used for? (2)
- reactions like protein synthesis. active membrane transport, muscle contraction, etc.
- little ATP stored, so constantly have to make it
