Cell Physiology (Flashcards)

Question 1

What is the role of the cell membrane in cell physiology?

Answer 1

The cell membrane is a dynamic and active participant in the cell’s interactions with its environment and is central to almost every aspect of human physiology, from cellular communication to whole-body homeostasis

Question 2

What is the cell membrane’s phospholipid bilayer’s function?

Answer 2

It is a continuous layer around the cell that acts as a barrier to water-soluble substances, but not to lipid-soluble molecules and small molecules like oxygen and carbon dioxide

Question 3

Name five types of membrane proteins and their functions.

Answer 3

• Transport Proteins:
  
  • Channels form pores for selected ions/molecules to move through. Carrier proteins bind to solutes and help carry them across the membrane
• Receptor Proteins:
  
  • Bind specific extracellular molecules (ligands) like hormones and neurotransmitters
• Enzymes:
  
  • Control chemical reactions on the outer or inner surface of the cell
• Joining Proteins:
  
  • Anchor the cell membrane to the cytoskeleton or an adjacent cell
• Identifying Proteins:
  
  • Identify the cell as “self” (part of the body)

Question 4

What is passive transport?

Answer 4

Movement of substances across the cell membrane that requires no energy (ATP) and moves substances from a high to low concentration

Question 5

Name four types of passive transport.

Answer 5

• Simple diffusion:
  
  • Solute diffuses directly through the cell membrane bilayer
• Channel-mediated facilitated diffusion:
  
  • Ions diffuse through membrane protein channels
• Carrier-mediated facilitated diffusion:
  
  • Large, charged, or water-soluble molecules diffuse across the membrane using a specific carrier protein
• Osmosis:
  
  • Movement of water across a semipermeable membrane due to a water concentration difference

Question 6

What is osmotic pressure?

Answer 6

The pressure required to prevent the movement of water across a semipermeable membrane due to osmosis, determined by the concentration of solutes in a solution. Water moves from areas of low osmotic pressure to areas of high osmotic pressure

Question 7

Define hypertonic, hypotonic, and isotonic solutions.

Answer 7

• Hypotonic:
  
  • ECF has a lower osmotic pressure (higher water concentration) than ICF, causing the cell to swell
• Hypertonic:
  
  • ECF has a higher osmotic pressure (lower water concentration) than ICF, causing the cell to shrink
• Isotonic:
  
  • ECF and ICF have equal osmotic pressures, so the cell neither swells nor shrinks

Question 8

What is active transport?

Answer 8

Movement of ions/molecules against their concentration gradient, requiring energy (ATP)

Question 9

What are primary and secondary active transport?

Answer 9

• Primary Active Transport:
  
  • ATP breakdown is directly part of the transport process (e.g., Na+/K+-ATPase pump)
• Secondary Active Transport:
  
  • Uses ATP indirectly, such as glucose absorption by enterocytes, where a Na+ gradient drives glucose transport

Question 10

What is vesicular transport?

Answer 10

Movement of substances into or out of a cell using vesicles (membrane-bound sacs). Types include endocytosis (into the cell) and exocytosis (out of the cell)

Question 11

What is the difference between phagocytosis and pinocytosis?

Answer 11

• Phagocytosis:
  
  • “Cell eating,” involving the movement of large items (e.g., bacteria) into the cell
• Pinocytosis:
  
  • “Cell drinking,” involving the movement of fluids and dissolved substances into the cell

Question 12

What is the overview of cell metabolism?

Answer 12

Cells are the living building blocks of the body, and the chemical processes they perform are called metabolism, which includes anabolism (building molecules) and catabolism (breaking down molecules)

Question 13

What is protein synthesis?

Answer 13

The process by which cells create proteins, such as enzymes, hormones, and structural components, involving DNA transcription and mRNA translation

Question 14

Briefly describe DNA transcription and mRNA translation.

Answer 14

• DNA Transcription:
  
  • A DNA template is copied into mRNA
• mRNA Translation:
  
  • mRNA is used to create proteins with the help of ribosomes and tRNA

Question 15

Describe cellular respiration.

Answer 15

The production of ATP using glucose, involving glycolysis (anaerobic) in the cytosol, followed by aerobic processes (Krebs Cycle and Electron Transport Chain) in the mitochondria

Question 15

What is ATP catabolism?

Answer 15

The breakdown of Adenosine Triphosphate (ATP) to release energy stored in phosphate bonds, which is used for reactions like protein synthesis, active membrane transport, and muscle contraction

Question 16

What substrates can the body use to produce ATP?

Answer 16

Carbohydrates (glucose), proteins (amino acids), and fats (triglycerides)