IB Biology 2.3: Carbohydrates & Lipids

Vocabulary practice flashcards covering energy storage, chemical structures, functions, types, and health associations of carbohydrates and lipids from IB Biology 2.3.

Lipids (Energy Storage)

Primary long-term energy storage compounds that contain $2$ times the amount of energy per unit as carbohydrates or proteins, release large sums of energy when their stable C-H bonds are broken, and are insoluble in water.

Carbohydrates (Energy Storage)

Short-term energy storage compounds that are easily digested for rapid energy release, stored as glycogen in animal muscles and liver, and more soluble in water in simple forms (monosaccharides and disaccharides) for easy transport.

Atheroma

Fat deposits that develop inside arteries, reducing the diameter of the lumen needed for pulse flow, which can lead to blood clots and potential heart attacks.

Coronary Heart Disease (CHD)

A cardiovascular condition positively correlated with excessive dietary fat intake, high blood pressure, saturated fatty acid consumption, and trans-fat deposits in arterial walls.

Saturated Fatty Acids

Fatty acids in which all carbon atoms carry as many hydrogen atoms as possible with no double bonds; commonly found in animal fats, butter, milk, and cheese, and linked to atherosclerosis and coronary heart disease (CHD).

Monounsaturated Fatty Acids

Fatty acids that contain exactly one carbon-carbon double bond, resulting in two empty hydrogen spots along the hydrocarbon chain.

Polyunsaturated Fatty Acids

Fatty acids containing at least two carbon-carbon double bonds in their hydrocarbon chain; typically derived from plant sources such as olive oil.

Cis Fatty Acids

Unsaturated fatty acids where hydrogen atoms are attached to the same side of the double bond, creating a bent hydrocarbon chain that remains liquid at room temperature.

Trans Fatty Acids

Unsaturated fatty acids where hydrogen atoms are attached on opposite sides of the double bond, producing a straight chain with a higher melting point that is solid at room temperature and strongly linked to atherosclerosis and CHD.

Phospholipids

Lipid molecules that function as the main structural component of cell membranes.

Steroids

Lipid compounds involved in hormonal signaling, with examples including estrogen and testosterone.

Myelin Sheath Lipids

Specialized lipids surrounding the axons of neurons that serve as electrical insulators.

Triglycerides

Lipid molecules composed of glycerol and three fatty acids that function as a long-term energy storage source and form a protective tissue layer around key internal organs against physical injury.

Glucose

A foundational monosaccharide used by cells for energy and serving as the primary building block of larger carbohydrates.

Galactose

A monosaccharide sugar that combines with glucose to form the disaccharide lactose.

Fructose

A sweet monosaccharide found naturally in fruits and sweet root sources such as honey and onions.

Lactose

A disaccharide composed of glucose and galactose, produced by mammals and found in milk.

Maltose

A disaccharide composed of two linked glucose molecules, commonly utilized in seeds.

Sucrose

The most prevalent disaccharide, utilized by plants to transport sugars throughout their tissues.

Polysaccharides

Complex carbohydrates consisting of straight or branched chains of many sugar monomers, most commonly composed entirely of glucose, serving as energy storage or structural molecules.

Starch

A glucose polysaccharide used by plants to store surplus glucose in plastids and chloroplasts, which can be broken down by animal digestive enzymes.

Cellulose

A structural polysaccharide that composes cell walls in plant cells; indigestible by most organisms, but necessary as dietary fiber for a healthy diet.

Glycogen

A polysaccharide used by animals to store surplus glucose in muscles and the liver for short-term energy storage.

Body Mass Index (BMI)

A diagnostic indicator of an individual's relative weight versus height, calculated using the formula: $\text{BMI} = \frac{\text{mass in kg}}{(\text{height in meters})^2}$.

Underweight (BMI Status)

A Body Mass Index category defined by a calculated BMI value below $18.5$.

Normal Weight (BMI Status)

A Body Mass Index category defined by a calculated BMI value ranging from $18.5$ to $24.9$.

Overweight (BMI Status)

A Body Mass Index category defined by a calculated BMI value ranging from $25.0$ to $29.9$.

Obese (BMI Status)

A Body Mass Index category defined by a calculated BMI value of $30.0$ or higher.