Chapter 3 - Biological Macromolecules Flashcards
Biological Macromolecules
large molecules, necessary for life, built from smaller organic molecules; organic: contain C
4 Major Macromolecules
carbohydrates, lipids, proteins, nucleic acids
-make up majority of cells dry mass
Monomers
building blocks, single subunits that make up macromolecules
-combine with each other with covalent bonds to form larger molecules - polymers
-releases water as byproduct
Dehydration Synthesis
A hydrogen of 1 monomer combines with the hydroxyl of another monomer
-monomers share electrons and form covalent bonds
-chain of repeating monomers = polymer
Hydrolysis
Opposite of Dehydration Synthesis
-polymers break down into monomers, and a chemical reaction occurs when inserting H2O across a bond - breaking a covalent bond with water molecules causes the polymer to break into 2 components: one part gains H+ and the other gains OH-
-break bond = release energy
Monosaccharides
basic unit to make carbohydrates, simple sugars
-can be directly metabolized without further breakdown
-most common: glucose, then fructose, galactose, xylose
-# of carbons ranges from 3-7
-most names end in ose
Carbohydrates
organic compounds that contain C, H, and O in a ratio of 2 H atoms & 1 O for every 1 C (C6 H12 O6)
-one of the body’s main energy sources
-two forms : complex and simple
glucose + glucose
maltose
fructose + glucose
suctose
galactose + glucose
lactose
xylose or ribose + 5C
peltose
Carboxyl Group
C (=0) H
Aldose
End of Chain
Ketose
Middle of Chain
Glucose
C6 H12 O6
-an important source of energy (during cellular respiration, energy releases from glucose which helps make adenosine triphosphates (atps)
-plants synthesize glucose using carbon dioxide and water, glucose provides energy requirements for plant
-humans/animals that eat plants often store excess glucose as catabolized (cell breakdown of larger molecules) starch
Fructose
sucrose, found in fruit
-both same chemical formula, differ structurally and chemically because of diff arrangements of functional groups around asymmetric carbon
-fructose and glucose are isomeric monosaccharides and have same formula but different structures
Disaccharides
when 2 monosaccharides undergo a dehydration reaction (or condensation or dehydration synthesis)
-one monosaccharide’s hydroxyl group combines with another’s hydrogen which releases water molecule and forms the new molecule
-common: lactose, maltose, sucrose
Glycosidic Bond
covalent bond forms between a carbohydrate molecule and another molecule, between 2 monosaccharides
-can be alpha or beta type
Alpha Glucose
starches - we an metabolize
-when OH group on C-1 of first glucose below ring plane
Beta Glucose
plant cell, we cannot make energy from them
-when OH group on C-1 of first glucose is above ring plane
Amylase
saliva; can break down starch - we don’t have enzymes to break down beta glucose
Polysaccharides
a long chain of monosaccharides linked by glycosidic bonds
-may be branched or unbranched
-may contain diff types of monosaccharides
-molecular weight may be 100,000 Daltons or more - depending on # of monosaccharides
-starch, glycogen, celluslose, chitin
Glycogen
the storage form of glucose in humans and other vertebrates, comprised of monomers of glucose
-the animal equivalent of starch
-highly branched molecule (usually on liver or muscle cells)
-when blood glucose levels decrease, glycogen breaks down to release glycose in process scientists call glycogenolysis
Cellulose
most abundant natural biopolymer
-mostly comprises a plant’s cell wall; provides cell structural support
-every other glucose monomer is flipped over and monomers are packed tightly as extended long chains - creating rigidity and high tensile strength
Chitin
polysaccharide containing Nitrogen
-major component of fungal cell walls
Input and Output of Dehydration Synthesis
Input :
2 Glucose, Energy (ATP)
Output :
H2O, Maltose (new molecule)
Makeup of Carbohydrates
C1 H2 O1
of Carbons in Di/Oligo/Polysaccharides?
Disaccharides - 2 C
Oligosaccharides - 3 -10 C
Polysaccharides - more than 10 C
Why do disaccharides and oligosaccharides take longer to digest than monosaccharides?
Because they require more water and time.
Differences between Glucose and Fructose
Glucose - primary source of energy, 80% intestines, 20% liver, not turn directly into fat, 80% burned by cells, 20% stored as glycogen, cholesterol friendly * metabolized for energy or packaged for energy storage
Fructose - toxic time bomb, only liver can process it, makes up fat, converted to fat directly, promotes bad cholesterol (30% converted) * converted to fat storage
High Fructose Corn Syrup
linked directly to obesity, diabetes, and metabolic dysfunction
-found in yogurt, bread, frozen pizza, cereal bars, cocktail peanuts, mac and cheese, salad dressing, tomato-based sauces, apple sauce, canned fruit
-causes: weight gain, type II diabetes, hypertension/high blood pressure, triglycerides, gout, non-alcoholic fatty liver disease, kidney stones
Polysaccharides
10-100s of monosaccharides linked together by dehydration synthesis
-includes starch (potatoes), amylopectin, glycogen (all three can be metabolized by humans),
and cellulose - which humans do not have the enzymes to break down (plant cells)
-slowest carb to be digested because they are the most complex
2 Forms of Plant Starch
Amylose - glucose molecules linked together like strings
Amylopectin - a complex network of glucose molecules that includes cross-linkages between strings
Soluble Fibers
-decreases cholesterol
-prevents heart disease
Insoluble Fibers
-promotes bowel movements
-relieves constipation
