Topic 8: Cell Physiology 2 - Basic Cell Processes

Question 1

What are cells?

Answer 1

• living building blocks of the body

Question 2

What is metabolism?

Answer 2

chemical processes in the body performed by cells

Question 3

What is anabolism?

Answer 3

building molecules

Question 4

What is catabolism?

Answer 4

• breakdown of molecules

Question 5

What are the 3 steps in protein synthesis?

Answer 5

• DNA transcription
• mRNA translation
• After translation

Question 6

What can proteins be?

Answer 6

• enzymes, structural, etc.

Question 7

What occurs in DNA transcription? (3)

Answer 7

• 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

Question 8

What occurs in mRNA translation? (4)

Answer 8

• 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

Question 9

What is a codon? (2)

Answer 9

3 bases on mRNA (base triplet)
- each codon codes for 1 aa, but aa can have more than one codon

Question 10

Give a summary from transcription to protein using sequence of bases of DNA

Answer 10

• sequence of DNA bases determines mRNA sequence. which determines aa sequence for protein

Question 11

What occurs in the after translation phase? (2)

Answer 11

• 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

Question 12

What happens after proteins are released into the ER? (3)

Answer 12

1. modified by adding sugars (polypeptides)
2. Transferred to golgi complex in vesicles
3. Golgi further modifies proteins

Question 13

What does the golgi do to proteins? (3)

Answer 13

• 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)

Question 14

What are lysosomes?

Answer 14

• membrane-bound organelles containing digestive enzymes (acid environment)

Question 15

What are the functions and characteristics of enzymes? (5)

Answer 15

• names usually end in -ase
• increase reaction rates
• not used up in rxn
• very sensitive to pH, temp
• very specific

Question 16

What is ATP? (2)

Answer 16

• adenosine triphosphate
• adenine + ribose (adenosine) and 3 phosphates

Question 17

Where is energy stored in ATP?

Answer 17

• in phosphate bonds (COVALENT)

Question 18

What is energy produced from ATP used for? (2)

Answer 18

• reactions like protein synthesis. active membrane transport, muscle contraction, etc.
• little ATP stored, so constantly have to make it