BIOS 256 Week 3 Case Study Metabolism

Student Name

Chamberlain University

BIOS-256: Anatomy & Physiology IV with Lab

Prof. Name

Date

Case Study 2: BT

History

BT is a 36-year-old woman presenting with dysuria (painful urination) and increased urinary frequency lasting for the past two days. She does not report having a fever or any additional systemic symptoms. During the clinical interview, she admitted to consuming less water than usual, which may have contributed to her urinary discomfort.

Physical Examination

On physical assessment, her abdomen was soft, non-tender, and without palpable masses. No signs of costovertebral angle tenderness were observed, which helps rule out an upper urinary tract infection such as pyelonephritis.

Laboratory Results

Urinalysis using a dipstick test showed the presence of both leukocytes and nitrites, confirming a urinary tract infection (UTI). Additionally, ketones were detected in the urine (ketonuria), which was an unexpected finding. This abnormality suggests altered metabolism, requiring further evaluation to determine potential underlying causes such as impaired glucose utilization or excessive fat breakdown.

Deliverables

1. Two Potential Causes of Ketonuria

Ketonuria occurs when ketone bodies accumulate in the urine, typically reflecting increased fat metabolism. Possible causes include:

2. Nutrient Involved in Ketone Formation

Ketones are formed when carbohydrate availability is limited and glucose cannot adequately supply energy needs. As a result, the body metabolizes fats as an alternative fuel source. Fatty acids become the primary nutrient involved in ketone production, with their oxidation in the liver leading to the formation of ketone bodies such as acetoacetate, beta-hydroxybutyrate, and acetone.

3. Describe Lipolysis and Ketone Formation

Lipolysis is the biochemical process where stored triglycerides are broken down into glycerol and free fatty acids. When glucose levels are insufficient (as in fasting, prolonged exercise, or diabetes), fatty acids undergo beta-oxidation in the liver. This process generates acetyl-CoA, which exceeds the capacity of the Krebs cycle and is instead diverted to form ketone bodies. These ketones circulate in the blood and serve as an alternative energy source, particularly for the brain, skeletal muscle, and cardiac tissue.

4. Is Lipolysis Anabolic or Catabolic?

Lipolysis is a catabolic process. Catabolic pathways involve the breakdown of large, complex molecules into smaller units, releasing energy in the process. During lipolysis, triglycerides are degraded into fatty acids and glycerol, which the body uses to generate energy when glucose is not readily available.

5. Predict the Effect of Excess Ketones on Blood pH

When ketones accumulate beyond the body’s buffering capacity, blood pH decreases, leading to metabolic acidosis. This condition, known as ketoacidosis, is most commonly associated with uncontrolled diabetes mellitus (diabetic ketoacidosis). Clinically, ketoacidosis can present with symptoms such as rapid breathing (Kussmaul respirations), confusion, dehydration, and, if untreated, can progress to coma. Maintaining acid-base balance is therefore critical to prevent these complications.

References

American Diabetes Association. (2022). Standards of medical care in diabetes—2022. Diabetes Care, 45(Supplement_1), S1–S264. https://doi.org/10.2337/dc22-Sint

Ketones. (2021). How the body processes sugar. University of California, San Francisco. https://dtc.ucsf.edu/types-of-diabetes/type2/understanding-type-2-diabetes/how-the-body-processes-sugar/ketones

BIOS 256 Week 3 Case Study Metabolism

Mahan, L. K., Raymond, J. L., & Escott-Stump, S. (2020). Krause’s food & the nutrition care process (15th ed.). Elsevier.