Biological Macromolecules

What are the four types of carbon-based macromolecules? How do they differ?

Lipids, carbohydrates, proteins, and nucleic acids
unique structure and function

Monomers

The small units or building blocks for polymers/macromolecules

Macromolecule: carbohydrate
Monomer name: ?
Functions: ?
Example:

Sugar
Stores energy and structural material
Potato

Macromolecule: Lipid
Monomer name:
Functions:
Example:

Fatty acid
Store energy + form membrane + steroids
Fat cells

Macromolecule: Proteins
Monomer:
Function:
Example:

Amino acid
Enzymes, structural material, peptides
Hair

Macromolecule: Nucleic acids
Monomer:
Functions:
Example:

Nucleotide
Store genetic info
DNA

Polymers

Organic molecules that are composed of chains of subunits (monomers)

What is important about polymers?

It dictates how everything in the human body is built

How are organic polymers synthesized?

By bonding together monomers with special types of covalent bonds

Condensation reaction

Also known as dehydration synthesis
•process of joining monomers to monomers or monomer to polymers or polymers to polymers
•each reaction yields a single molecule of water (water is generated but at the same time lost)

How are polymers broken down?

By breaking the covalent bonds that link the monomers

Hydrolysis reaction

The breakdown process of polymers
•each reaction used a single molecule water to split a large molecule into monomeric subunits
•gains a water in the new chemical formula

Hydrophobic

Water fearing (usually nonpolar)

Hydrophilic

Attracted to water (usually polar)

Lipid

Carbon-containing biological molecules that is largely nonpolar and hydrophobic

What are lipids mostly made up of?

Hydrocarbons

Hydrocarbons

Long chains of carbon covalently bonded with hydrogen atoms filling their valence shells (sometimes oxygen as well)

What are the building blocks of lipids?

Fatty acids

What is fatty acid made up of?

Hydrocarbon chain that is bonded to a carboxylic acid (COOH) functional group

How many carbon atoms do fatty acids have? How are they synthesized?

Even number of carbon atoms
•joining of two carbon acetyl groups

Saturation

How many carbon-valence positions are filled with hydrogen atoms

Unsaturated fatty acids and bonds

Possess one or more double covalent bonds between carbon atoms
•this produces a kink/bend = prevents rotation, limits flexibility and changes the overall shape of fatty acid

What is the difference between saturated and unsaturated fats at room temp?

Saturated fats are able to make many connections with its carbon bonds
•these connections squeeze against one another and it takes a lot of energy to break them
=this makes saturated fats solid at room temp
Unsaturated fats have a kink which does not allow the carbon atoms to be packed together tightly
•it takes less energy to break these bonds
=unsaturated fat is a liquid at room temp

Examples of saturated fatty acids

Meat, dairy, butter, muscle fat (lard)
•stearic acid, arachidic, palmatic

Examples of unsaturated fatty acids

Mono-unsaturated: olive oil, canola oil, avocados, 1 C=C bond

Poly-unsaturated: corn oil, fatty fish multi C=C bonds
•oleic acid, erucic acid

Examples of polyunsaturated fatty acids

Arachidonic, linoleic, linolenic

What shape does saturated fatty acids take?

Long linear shape

cis unsaturated fatty acid

hydrogen atoms are nearly always on the same side of the two carbon atoms that are double bonded, low melting point, oils/liquids

Cis unsaturated fatty acid shape

A bent or V shape

Poly unsaturated fatty acid shape

Usually takes in a U shape (many kinks)

trans fats shape and other name

fatty acids with hydrogens on opposite sides of the double bond
•partially hydrogenated oils (bad for us)

How is trans fatty acids made? And history?

When cooking it is easy when oils are in there solid form (such as butter with cookies)
•not possible with saturated fast bc of its properties
•saturated fat is expensive (animals) and hard to use at times if it's liquid
-cheaper too produce plant based oils
Crisco= taking plant based oils and bubbling hydrogen gas through the oil
•hydrogenate the fat, not fully but partially saturated
-causes hydrocarbon chain to loose it's kinks; rearranges into linear shape

Hydrogenate

To add hydrogen to unsaturated fats

Is trans fats bad?

Our bodies transport it differently, it caused artherosclerosis and other heart problems

Four types of lipids found in cells, how do they differ?

Fats (triglycerides)
Phospholipids
Steroids
Waxes
•differ in shape and function, how they bring fatty acids together

What is the monomer of lipids?

Fatty acids

What is the polymer fatty acids?

lipids

How do plants use wax?

They have an outer layer to prevent water from escaping
•keeps them hydrated

Fats other name

Triglycerides

Parts of a triglyceride

1 glycerol (3 carbon molecule with hydrogen and hydroxyl groups) and 3 fatty acids/hydrocarbon chain (monomers)

How are triglycerides formed?

Created through condensation reactions
•carboxylic acid group (COOH) of fatty acid joins the hydroxyl groups (3; OH) of glycerol

What type of covalent bonds are formed between fatty acids and glycerol?

Ester linkages

What is produced when 3 fatty acids combine with glycerol?

A lipid and 3 water molecules

Why are fats a good source of energy?

Metabolism creates energy by breaking covalent bonds, there are many covalent bonds in a fatty acid hydrocarbon chain

What do phospholipids consist of?

2 fatty acid chain connected to glycerol connected to a phosphate group (PO4^3-)

How are phospholipids made?

Condensation reaction (same as triglycerides)

What is so special about the phosphate group in a phospholipid

It is a polar molecule and the fatty acids are nonpolar
This creates an amphipathic chemistry

ampipathic

A molecule that has a both a hydrophilic (polar) region and a hydrophobic (nonpolar) region

What is the "head" of a phospholipid?

The polar side of the molecule (hydrophilic)
•phosphate group
=causes it to interact with water

What is the tail of a phospholipid?

Non-polar side (hydrophobic)
•made of fatty acids (hydrocarbon chains)
=repels water

What is the primary function of phospholipids?

To form membranes

What are the purpose of membranes?

To create boundaries between the inside of the cell (organelles) and outside of the cell

What happens when a phospholipid is placed in water?

The polar head interacts with water while the nonpolar tail repels water
•they immediately arrange themselves into a double layer, with the heads on the outside (interacting with water) while the tails are insulated on the inside
=creates a bilayer membrane

Steroids structure

Unique lipids, made up of four ring structure

How are the rings of steroids made?

Cyclizing a special triterpenoid hydrocarbon (fatty acid) called squalene

How are the rings of steroids made (easy def)?

Take fatty acids, stringing together into longer chains and lastly folding them up into ring based structures

Precursor to steroid?

Squalene, made up of many difft fatty acids stringed together

Examples of steroids

cholesterol, estrogen, testosterone, oestrone, cholic acid, corticotestosterone

How are steroids signaling molecules?

They act like hormones and tell your body what to do

Carbohydrates structure (basic)

Hydrated hydrocarbons
Because it's structure is simply carbon bonded to water multiple times
•(CH2O)n

Monosaccharide

Repeating chains of hydrated carbons
•simple sugars
•building blocks of carbohydrates (monomers)

Polysaccharide

Another name for carbohydrate
•polymer of carbs (multiple monomers)

How do carbs interact with water?

Due to the presence of oxygen/water (which is more electronegative) it causes the molecule to become polar
•carbs are hydrophilic/will dissolve in water

What are the 3 different criteria used to identify simple sugars?

Number of carbon atoms, location of carbonyl group, and spatial arrangement of their atoms

Sugar with three carbon atoms

Triose sugar

Sugar with 5 carbon atoms

pentose sugar

Sugars with 6 carbon atoms

Hexose sugar

What does the suffix -ose mean?

Carbohydrate

Carbonyl group

C=O
Specific functional group; carbon atom double bonded to an oxygen atom

Ketone group

carbon double bonded to an oxygen (carbonyl group) with a bond to carbon on either side (in middle of monosaccharide)
C
|
C = O
|
C

Ketose sugars

When the carbonyl group is found in the middle of the carbon chain and forms a ketone group

Aldehyde group

Forms when the carbonyl group is located at the terminal end of the carbon chain and bonds with a hydrogen
H-C=O

Aldose sugars

When the carbonyl group is located at the terminal end of monosaccharide and forms an aldehyde group

What does the functional group placement in sugars dictate?

It dictates the type of chemistry the monosaccharide can participate in (structure relates to function)

Which compound is especially important in terms of the spatial arrangement of carbohydrate atoms?

Hydroxyl (OH-) group
Defines the type of simple sugar it is

Glucose function and examples

Primary brain food and is the basic part of all sugars
•starches, sucrose, artificial sweeteners

Galactose function and examples (comparing to glucose)

Brain can't eat this so it has to convert it into glucose
•part of milk sugar so some can't digest is lactose intolerant

Isomers

Compounds with the same formula but different structures
•ex: glucose v galactose

What happens when a monosaccharide such as glucose is dissolved in water or in solid form?

The covalent bonds will have the ability to rotate around one another, which allows glucose to rotate into a six-members ring structure

Why does the ring structure form when glucose dissolves in water?

It is more stable in that structure than in linear form

What are the six-members rings called?

Hemiacetals

What is the final step to from the ring structure of glucose? What does it produce?

Oxygen atoms becomes bonded to a carbon atom to close off the ring
The ring now has a carbon point bonded to one hydrogen atom and one hydroxyl group
•two different ways these two groups can be structured

What are the two ways the carbon ring can form?

The hydroxyl group can be placed either down in orientation (other side of carbon 6) or up in orientation (same side of carbon 6)

C-OH in a down orientation called...

Alpha glucose

C-OH in an upward orientation called ...

Beta glucose

Anomers of glucose

Related molecules that are configured/structures in a slightly different manner in terms of the hydroxyl group

Alpha glucose when consumed...

Provides energy which allows someone to run a marathon

Beta glucose when consumed...

Acts like fiber and causes someone to have great poops

Polysaccharide

The polymer of carbs which is formed from the condensation reaction of monomers (monosaccharides)
•hydroxyl groups react together to create an oxygen and water molecule

What is special about the linkage between two monosaccharides?

It is a covalent bond between oxygen (not carbon)
•called glycosidic linkage
The monomers can be identical or difft and the location of the bond can vary

What is it called when glucose and fructose bond?

A glucose/fructose disaccharide = sucrose (table sugar)

Because monosaccharides can form a wide variety of structures/configuration, it perform...

A wide variety it functions
•building blocks in the synthesis of other molecules
•indicate cell identity
•store chemical energy
•provide cells with fibrous structural material

How do polysaccharides give identity to a cell?

They decorate the cell from the outside by forming glycoproteins and glycolipids
•the glycoproteins function in cell to cell recognition and signaling

Glycoproteins and glycolipids

Sugars that have been joined to proteins and lipids by strong covalent bonds on the cell membrane

How do glycoproteins and glycolipids act as recognition?

These molecules are unique for individuals (not the same for everyone)
•When activated, immune cells travel to other body cells and interact with these molecules on the cell membrane
•if the molecules don't match the other cells in the body, immune cells will attack
-organ/tissue transplants are rejected in this way

Why are carbs such an efficient form of energy?

They contain an abundance of carbon-hydrogen and carbon-carbon bonds which can be broken down to release energy

Lipids vs Carbs energy storage

Lipids are able to store more energy per unit than carbs/more dense
•can make a candle out of fat but not out of sugar

How do plants store carbs?

As starch

How do animals store sugar?

As glycogen

What do starch and glycogen have in common?

They are nothing more than a-glucose monomers joined by alpha 1, 4-glycosidic linkages