Chapter 3 - Biological Macromolecules Flashcards
4 major biological macromolecule classes
Carbohydrates, lipids, proteins, nucleic acids
What makes up most of a cells mass?
Water
What are the building blocks of macromolecules?
Monomers are, since macromolecules are polymers themselves
When monomers combine with polymers what happens? What is the reaction called?
The reaction is called dehydration synthesis, it causes the monomers to release water molecules as byproducts when combining to make polymers
What happens with the atoms in a dehydration synthesis reaction?
The hydrogen (H+) of one monomer combines with the hydroxyl group (OH-) of another monomer releasing H2O, at the same time the monomers share electrons and form covalent bonds
What do dehydration synthesis reactions require to form new bonds
Input of energy
Glucose monomers can give rise to what molecules?
Starch, glycogen, cellulose, …. polymers
Polymers break down into monomers during what type of reaction?
Hydrolysis
Both dehydration synthesis and hydrolysis reactions are catalyzed by what?
Enzymes
During hydrolysis what happens with the bonds?
They break and release energy
During hydrolysis the polymer breaks into 2 components; what are they?
They are both monomers; one monomer gains a hydrogen (H+) and the other gains (OH-) a hydroxyl group from a split H2O molecule
What type of enzymes break down carbohydrates, lipids, and proteins?
Can any enzyme break down them?
No, they require specific enzymes to break down each macromolecule
Example: amylase, sucrase, lactase, Maltase, galactase, ect… for carbohydrates
Proteases such as pepsin, peptidases, and hydrochloric acid for proteins
And lipases for lipids
(ALL releasing energy for cellular activity)
What is the stoichiometric formula for carbohydrates?
(CH2O) ratio of 1:2:1
What are the 3 subtypes of carbohydrates?
Monosaccharides, disaccharides, and polysaccharides
What are simple sugars?
Monosaccharides
What is the most common monosaccharide?
Glucose
What is the normal carbon range for simple sugars?
3-7
Monosaccharides usually end with what suffix
-ose
What are aldoses?
Simple sugars with a CHO functional group (aldehyde group) that is on one end of the molecule
Structure R-CHO
What are ketoses?
They are simple sugars with a C=O functional group (NOT on the end) forming a ketone functional group
Structure: RC(=O)R
Depending on what in the sugar can they be called trioses, pentoses, and hexoses?
The number of carbons
What is the primary energy producing molecule in humans? What is its chemical formula?
Glucose (C6H12O6)
During cellular respiration energy releases from glucose helps make what?
ATP (adenosine triphosphate)
Photosynthesis uses what to produce glucose?
CO2, H2O, and light
What is similar and different about galactose, fructose and glucose?
They are monosaccharides that all have the same chemical formula (C6H12O6) but differ in structure, this means they are isomers of each other due to different arrangement of functional groups and the asymmetric carbon
What is the shape of monosaccharides? What shape are they usually in an aqueous solution?
They can exist as a linear chain or as ring-shaped molecules; in aqueous solution they are usually ring shaped
The ring form of glucose can have 2 forms. What are those 2 forms?
if the hydroxyl group is below the number 1 carbon it is the alpha form
If the hydroxyl group is above the number 1 carbon it is the beta form
How do disaccharides form? What bond is made?
When 2 monosaccharides undergo a dehydration reaction forming a covalent bond called a glycosidic bond
Glycosidic bonds can be what type? What does it depend on?
They can be alpha with the hydroxyl of the number 1 carbon below the ring plane and beta with the hydroxyl above the ring plane
Sucrose (table sugar) forms when what happens?
The glycosidic bond is between the number 1 carbon of glucose and the number 2 carbon of fructose
Lactose (milk sugar) forms when what reacts?
Glucose and galactose bond (react)
Maltose (grain sugar) form when what bonds
2 glucoses bond (react)
Depending on what does it decide the Polysaccharide being made?
If they are branched or unbranched, and what monosaccharides they are
List some polysaccharides
Starch, glycogen, cellulose, chitin
What are the 2 main plant starches?
Amylose (unbranched 1-4 alpha linkages) and amylopectin (branched, 1-4 alpha and 1-6 linkages)
*polysaccharides is how plants store glucose in their roots and seeds
What is the point of humans producing salivary amylase?
To break down amylose into smaller molecules like glucose and maltose when it is in the mouth, it then can be absorbed into cells and used
Where is glycogen usually found? What is its structure?
It is found in humans and other vertebrates, more specifically it is usually stored in muscles and liver. It is also a highly branched structure
What happens when blood glucose levels decrease? What process happens?
Glycogen breaks down to release glucose in a process called glycogenolysis
What is the most abundant natural biopolymer?
Cellulose
Where is cellulose usually found in nature? And what is special about it’s structure?
It mostly comprises a plants cell wall - it is a beta 1-4 glycosidic polysaccharide which allows the glucose monomers to pack in tightly and form long chains with high rigidity and tensile strength (every other glucose is flipped)
Why can humans not digest cellulose?
Because humans don’t have the enzymes necessary to break down beta 1-4 linkages, only few bacteria and protistan species can produce the enzyme cellulase which allows them to break down cellulose into glucose
What is chitin? Where is it used? And what is it’s composition?
A polysaccharide found in anthropods and fungi that is composed of N-acetyl-beta-d-glucosamine units (modified sugars), it is also a major component of fungal cell walls
What is the cells primary energy source that produces ATP?
Glucose