1.4.3 Cholesterol

• What substance synthesized from cholesterol aids in fat digestion?

  Bile acids
• Cholesterol helps maintain membrane fluidity under different temperature conditions.
• At low temperatures, cholesterol prevents close packing of fatty acid tails, increasing membrane fluidity.
• What type of lipid is cholesterol?

  Steroid
• Cholesterol contributes to the rigidity and fluidity of cell membranes.
• Cholesterol is involved in the synthesis of steroid hormones like estrogen and testosterone.
• What are the two main forms of lipoproteins that transport cholesterol in the blood?

  LDL and HDL
• The steroid nucleus in cholesterol is made of four fused carbon rings.
• Where is the hydroxyl group attached in the cholesterol structure?

  Ring A, position 3
• The hydroxyl group in cholesterol allows it to interact with water due to its polarity.
• What is the role of cholesterol in cell membranes at low temperatures?

  Increases fluidity
• Match the lipoprotein with its role and effect on heart health:

  LDL ↔️ Transports cholesterol from liver to tissues; high levels increase heart disease risk

  HDL ↔️ Transports cholesterol from tissues to liver; high levels reduce heart disease risk
• Order the effects of cholesterol on membrane fluidity under different temperature conditions:

  1️⃣ Low temperature: Prevents close packing of fatty acid tails

  2️⃣ Low temperature: Increases membrane fluidity

  3️⃣ High temperature: Interacts with phospholipid tails

  4️⃣ High temperature: Decreases membrane fluidity
• Which steroid hormone is cholesterol a precursor for?

  Testosterone
• Cholesterol is essential for maintaining the rigidity and fluidity of cell membranes.
• What type of hormones is cholesterol a precursor for?

  Steroid hormones
• At high temperatures, cholesterol interacts with phospholipid tails to decrease membrane fluidity.
• What health risks are associated with high cholesterol levels?

  Cardiovascular disease and stroke
• LDL transports cholesterol from the liver to tissues.
• Cholesterol maintains the rigidity and fluidity of cell membranes
• What are the two properties of cell membranes that cholesterol helps maintain?

  Rigidity and fluidity
• Arrange the effects of cholesterol on membrane fluidity at different temperatures:

  1️⃣ Low temperature: Prevents close packing of fatty acid tails

  2️⃣ Low temperature: Increases membrane fluidity

  3️⃣ High temperature: Interacts with phospholipid tails

  4️⃣ High temperature: Decreases membrane fluidity
• High cholesterol is linked to increased cardiovascular disease and stroke
• High levels of HDL are protective against heart disease.
• Match the lipoprotein with its function and health impact:

  LDL ↔️ Transports cholesterol to tissues ||| High levels increase plaque buildup

  HDL ↔️ Transports cholesterol to the liver ||| High levels reduce heart disease risk
• LDL transports cholesterol from the liver to tissues
• What is the primary function of HDL cholesterol?

  Remove cholesterol from tissues
• LDL is commonly referred to as "bad cholesterol" because it increases the risk of heart disease.
• Cholesterol is a type of lipid that functions as a steroid
• Match the component of cholesterol with its description and function:

  Steroid Nucleus ↔️ Four fused carbon rings ||| Forms the backbone

  Hydroxyl Group (-OH) ↔️ -OH attached to ring A ||| Provides polarity

  Alkyl Side Chain ↔️ Fatty chain attached to ring D ||| Contributes to hydrophobic properties
• What role does cholesterol play in cell membrane structure?

  Maintains rigidity and fluidity
• Cholesterol is a precursor to steroid hormones such as estrogen and testosterone.
• Cholesterol is used by the liver to produce bile acids, which aid in fat digestion
• What two properties does cholesterol help maintain in cell membranes?

  Rigidity and fluidity
• At low temperatures, cholesterol prevents the close packing of fatty acid tails, which increases membrane fluidity.
• What does cholesterol ensure by maintaining membrane fluidity?

  Proper functioning of cells
• At high temperatures, cholesterol interacts with phospholipid tails to increase membrane fluidity.

  False
• What is the term for cholesterol deposits in arterial walls that increase the risk of heart disease?

  Arteriosclerosis
• LDL carries cholesterol from the liver to tissues, while HDL transports it back to the liver for excretion.
• Maintaining balanced LDL and HDL levels is crucial for cardiovascular health.