Cell Biology and Homeostasis

• What is the smallest functional unit of the body?

  Cells
• What do stem cells do?

  They divide and differentiate into specialized cell types.
• What is the process called where different cell types work together?

  Tissues form organs, which form organ systems, leading to the body.
• What is necessary for healthy cell function?

  Optimal conditions are needed for chemical processes.
• What is homeostasis?

  It is a process that maintains optimal conditions in the body.
• What physiological limits must cells maintain for health?

  Oxygen, glucose, fluid and electrolytes, pH, and temperature.
• How do nurses use homeostatic parameters?

  They measure these parameters to prevent illness.
• What regulates homeostasis?

  Positive and negative feedback loops.
• What does negative feedback do?

  It opposes change to restore normal conditions.
• What does positive feedback do?

  It reinforces a change until an external force stops it.
• What must cells do to maintain homeostasis?

  Detect stimuli and respond accordingly.
• How do cells metabolize?

  They produce new substances and break down unneeded ones.
• What is the unit of energy used by cells?

  Adenosine triphosphate (ATP).
• What is metabolism?

  It is the collective term for all biochemical reactions in the body.
• What are the two types of metabolic reactions?

  Anabolic and catabolic reactions.
• What do catabolic reactions do?

  They break food down to release energy and building subunits.
• What do anabolic reactions do?

  They synthesize subunits into new macromolecules and ATP.
• What is the basal metabolic rate (BMR)?

  The minimum energy needed for vital organs to function.
• What factors increase metabolic rate?

  Gender, body mass index, pregnancy, and muscle activity.
• What factors decrease metabolic rate?

  Age and starvation.
• What are enzymes?

  Biological catalysts that facilitate biochemical reactions.
• How do substrates interact with enzymes?

  They bind to the active site of their specific enzyme.
• What happens to enzymes at high temperatures?

  They can denature and lose their function.
• What factors affect the rate of enzymatic reactions?

  Concentration of substrate and temperature.
• What suffix is commonly used for enzymes?

  • ase
• What is cellular respiration?

  A vital metabolic reaction that produces ATP.
• Where does glycolysis occur?

  In the cytoplasm.
• What are the three stages of cellular respiration?

  Glycolysis, citric acid cycle, and oxidative phosphorylation.
• How much ATP is produced in glycolysis?

  2 ATP.
• Where does the citric acid cycle occur?

  In the mitochondria.
• How much ATP is produced in the citric acid cycle?

  2 ATP.
• How much ATP is produced in oxidative phosphorylation?

  32-34 ATP.
• What happens to pyruvate in the absence of oxygen?

  It forms lactic acid instead of entering the mitochondria.
• What do cellular respiration and metabolism produce?

  ATP needed for metabolic reactions.
• What is a gene?

  A region of DNA that codes for one protein.
• What is the role of the nucleus?

  It controls cell function and contains DNA.
• What is transcription?

  The process of making mRNA from DNA.
• Where are ribosomes found?

  In the cytosol, either free or fixed to the rough endoplasmic reticulum.
• What are the two types of endoplasmic reticulum?

  Rough and smooth endoplasmic reticulum.
• What do ribosomes do?

  They read mRNA and bond amino acids to form polypeptides.