Carbohydrates and Lipids Review

Dehydration Synthesis

An anabolic reaction that takes small molecules and makes them into larger molecules by removing water

Hydrolysis

A type of catabolic reaction that breaks larger molecules into smaller molecules by adding water

Carbohydrate

A source of immediate energy, energy storage, or structural support. Known as sugars, starches, and fibers

Monosaccharide

Monomers of carbohydrates, “simple sugars” that provide energy. Examples: glucose, galactose, fructose

Disaccharide

Forms when two monosaccharides undergo dehydration synthesis w/ glycosidic bond. Examples: sucrose, lactose, maltose

Polysaccharide

Complex carbohydrate that forms when simple sugars bind together in a chain through dehydration synthesis. Examples: Starch, cellulose, glycogen, chitin

Glucose

Product of photosynthesis and directly used in energy production (ATP)

Fructose

Found in fruits, contains carbonyl, used in sucrose, has 5 sides

Galactose

Found in dairy, contains carboxyl, used in lactose

Sucrose

Table sugar, glucose + fructose

Lactose

Dairy, glucose + galactose

Maltose

“Malt” sugar, glucose + glucose

Starch

Plants store carbohydrates in the form of starch, made of glucose monomers. Amylose - spiral, Amylopectin - long branches

Amylose

Spiral chain of starch

Amylopectin

Long branches of starch

Glycogen

Stores energy for animals and other organisms, glucose monomers create highly branched molecule. Stored in liver and muscle in humans

Cellulose

Provides structural support for plant cells, can’t be digested by most animals - source of fiber. Most abundant polysaccharide, not very soluble. In grid/straight shape.

Chitin

Provides structural support in fungi and exoskeletons, long chain of modified glucose, insoluble due to hydrogen bonds

Glycosidic bond

Bond that joins 2 monosaccharides together into a polysaccharide

Lipid

Fats and oils that are composed of C, H, O, and some P or N. Hydrophobic, insoluble, largely nonpolar

Glycerol

3 carbon molecule with 3 -OH, known as the “head” of a triglyceride

Triglyceride

Formed through dehydration synthesis of glycerol and 3 fatty acids, forms ester bond. Provides long term energy storage, insulation, and cushions organs.

Phospholipid

Formed through dehydration synthesis, 1 phosphate head (polar and hydrophilic), glycerol, and 2 fatty acids. Makes up cell membranes known as phospholipid bilayer.

Phospholipid bilayer

Cell membrane, polar head and nonpolar tails

Steroid

4 ringed structure, acts as a “messenger", helps hormones, and a vitamin precursor. Examples: estrogen, testosterone, cholesterol

Cholesterol

Most common steroid, precursor to vitamin D, estrogen, and testosterone. Increases fluidity of cell membrane, can be either good or bad

Wax

Long chain fatty acid attached by ester bond to long chain alcohol, solid at room temp, protects and waterproofs (hydrophobic)

Saturated fatty acid

All single bonds and packed tightly with linear structure, solid at room temp, max # of hydrogen, source: animal fats and tropical plant oils, raises cholesterol

Unsaturated fatty acid

Has one or more double bond and fewer hydrogen, liquid at room temp, source: healthy oils, lowers cholesterol

Cis fatty acid

H same side of double bond which creates a bend

Trans fatty acid

H opposite side which makes it nearly straight, created by mankind, led to increased cholesterol through LDL

Ester bond

Hydrocarbon chain

Carboxyl group

Hydrophobic

Repelling and not mixing with water

Hydrophilic

Tendency to mix with, and interact with water

Amphipathic

Having both hydrophobic and hydrophilic parts

LDL (low density lipoprotein)

Transports cholesterol through the body and builds up in arteries, making them harder and narrow.

HDL (high density lipoprotein)

Picks up excess cholesterol and takes it back to your liver for disposal

Lipase

Breaks down triglycerides into glycerol and fatty acids

Anabolic reaction

Building larger molecules from small ones, requiring energy input

Catabolic reaction

Breaking down of larger molecules into smaller molecules with release of energy

Cellular respiration

Process in which cells break down molecules to release energy, transfers energy from food molecules

ATP (adenosine triphosphate)

The cell’s primary energy‑carrying molecule, used to power processes like muscle contraction, active transport, and chemical synthesis.

Isomer

Molecules with the same chemical formula but different arrangement