UNIT 1 - B 1.1 - Carbs and Lipids Flashcards
What are monosaccharides?
The smallest forms of carbohydrates
What does the formula for monocaccharides follow?
Cn H2n On, n=# carbon atoms
What are disaccharides?
two monosaccharides bonded together
What are polysaccharides?
many monosaccharides bonded together
How do lipids change based off of temperature?
They are oils at warmer temperatures and fats at cooler temperatures
What are the monomers of triglyceride lipids?
Molecules known as glycerol and fatty acids
What does the identity of a specific lipid depend on?
fatty acids
What is one function that both carbohydrates and lipids share?
To act as energy storage molecules
What four groups can the majority of molecules within all living organisms be categorized into?
carbohydrates, lipids, proteins, and nucleic acids
How is metabolism carried out?
The four categories of molecules interact with each other in a wide variety of ways
Why is life on earth described as “carbon-based”?
All the molecules in the four main categories contain carbon
What are three other common elements within the molecules of living organisms?
oxygen, nitrogen, and phosphorus
What are oxygen, nitrogen and phosphorus found in?
Carbohydrates, proteins, lipids and nucleic acids
What do oxygen, nitrogen, and phosphorus often form covalent bonds with?
Carbon and eachother
How many covalent bonds can hydrogen make?
1
How many covalent bonds can oxygen make?
2
How many covalent bonds can nitrogen make?
3
How many covalent bonds can phosphorus make?
5
How many covalent bonds can carbon make?
4
What are four common functional groups?
hydroxyl/alcohol (OH), amino/amine (NH2), carboxyl (COOH), phosphate (H2PO4)
What are the three subcategories of carbohydrates?
monosaccharide, disaccharide, polysaccharide
What are the three sub categories of lipids?
triglycerides, phospholipids, steroids
What is the sub category of nucleic acids?
nucleotides
What are macromolecules made up of?
monomers
What do hydrolysis reactions do?
break covalent bonds between monomers
What do hydrolysis reactions allow for in digestion?
breaking down macromolecules which is what most food ingested is in the form of
What is the monomer of carbohydrates?
monosaccharides
What are the monomers of lipids?
glycerol, fatty acids, phosphate groups
What is the monomer of proteins (polypeptides)?
amino acids
What is the monomer of nucleic acids?
nucleotides
After the ingested macromolecules are broken down, what do the resulting monomers do?
They are absorbed into the bloodstream and circulated to body cells
What often happens to monomers after entering cells?
They are built up into macromolecules again through the formation of covalent bonds in condensation reactions
What is a hydrolysis reaction?
a water molecules is split into two components and each component is added in and becomes apart of the two new (smaller) molecules
What do both condensation and hydrolysis reactions require?
Specific enzymes
How many products are always formed in condensation reactions?
2
What is always a reactant in a hydrolysis reaction?
water
What is a peptide bond?
After a water molecule is formed after a condensation reaction, the location where the hydroxide ion and hydrogen ion were released still contains a pair of electrons that form a new covalent bond - peptide bond is this covalent bond between two amino acids
What are condensation reactions catalysed by?
enzymes
Where are foods chemically digested?
in the ailmentary canal
what are hydrolysing enzymes?
digestive enzymes that accomplish chemical digestion
What happens to water molecules during hydrolysis reactions?
They split
What reactions make up a large part of overall metabolism?
sum total of condensation reactions and hydrolysis reactions
What is an example of a pentose monosaccharide?
ribose
What is the chemical formula for a pentose monosaccharide?
C5 H10 O5
What is an example of a hexose monosaccharide?
glucose
What is the chemical formula for hexose monosaccharides?
C6 H12 O6
What is glucose produced through?
photosynthesis
What is glucose used in?
Respiration
When glucose is used to make a polysaccharide, what purposes do the polysaccharids have?
Structural (ex. cellulose) and energy storage (ex. starch)
When looking at the structure of glucose, which functional group is found 5 times withing the molecule?
Alcohol/hydroxyl
Why is glucose a polar molecule?
The covalent bond between an oxygen atom and a hydrogen atom in glucose is a polar covalent bond
What are the four properties of glucose molecules?
molecular stability, high solubility in water, easily transportable, yields a great deal of chemical energy when covalent bonds are broken
What allows glucose molecules to have molecular stability?
Bonds within glucose are covalent bonds which are stable
Why is glucose highly soluble in water?
glucose is polar and dissolves readily in a polar solvent (water)
How is glucose easily able to circulate in blood and fluids between cells?
Because of its solubility in water
How do we know that glucose is a good energy store?
Due to the high energy yield in oxidation reactions
In nature, what is glucose in a polymer form often used for?
energy storage
What do plants do with the glucose after it is synthesized by photosynthesis?
store it as starch molecules
What is starch?
A polysaccharide made up of hundreds of glucose monomers
How do plants make starch as compact as possible?
It uses two different kinds of bonds between glucose molecules: alpha 1-4 linkage and alpha 1-6 linkage
What do the numbers of an alpha 1-4 linkage and an alpha 1-6 linkage refer to?
the carbon number of the two glucose molecules that are bonded together
What is amylose?
A type of starch that has an alpha 1-4 linkage
What shape does the resulting molecule of hundreds of glucose molecules bonded by 1-4 linkages have?
helix shape, but linear
What is amylopectin?
A type of starch bonded by 1-6 linkages
What do 1-6 linkages typically create in the structure of amylopectin?
branches
Why is starch not readily soluble in water?
Because its molecules are very large
Why is starch’s low solubility important for plants in particular?
They can easily store the starch
What is a purpose of condensation reactions in plants?
It allows the plant to add more glucose to amylose or amylopectin
What do plants do to use their reserves of glucose?
Hydrolysis reactions are used to break the glucose molecules away from starch
What is glycogen?
A polysaccharide made of glucose monomers
What is the pattern of the bonds between glucose monomers in glycogen similar to?
The 1-6 linkages in amylopectin
What is excess glucose stored as in many animals and humans?
glycogen
Where are glycogen reserves kept inside the human body?
Within our liver and muscle tissue
What is a primary advantage for organisms storing glucose as a polysaccharide?
The macromolecules are not readily soluble in cytoplasm and other fluids, meaning there is no effect on the osmotic balance in living tissues
What is the main structural difference between alpha glucose and beta glucose?
There is a reversal of H and OH at the right side of each molecule
Which form of glucose do starch and glycogen both use?
Alpha
What uses the beta form of glucose?
Cellulose
Why is cellulose estimated to be the mose abundant organic molecule on earth?
Because it is the primary component of the cell walls of plants
In cellulose, what do condensation reactions that bond one beta glucose molecule to the next require?
Every second beta glucose molecule to be oriented upside down compared to the glucose it is bonded to
What is the result of the structure of cellulose when beta glucose molecules form their 1-4 linkages?
A very linear polymer with no branches, similar to a long thin fibre
What is formed between parallel fibre-like polymers of beta glucose molecules in cellulose?
Hydrogen bonds
Why is cellulose stable?
Because the hydrogen bonds between the beta glucose polymers help hold the molecules together
What is the function of cellulose?
To act as a structural molecule in nature
What is a lipid + protein?
Lipoprotein
What is a carbohydrate + lipid?
Glycolipid
What is a carbohydrate + protein?
Glycoprotein
What are 5 functions membrane proteins are responsible for?
- cell to cell chemical communication (cell signalling)
- transport of molecules in and out of a cell
- cell to cell adhesion
- catalysis as a result of enzymes adhering to the inside or outside of the cell membrane
- recognition of body cells versus non-body cells for immune system functions
What determines a person’s ABO blood type?
Glycoproteins on the surface of red blood cells
What are antigens?
The two glycoproteins, A and B, on the plasma membrane of red blood cells
Why are the two glycoproteins, A and B, called antigens?
Because their presence can trigger the immune system
What will the immune system of someone with blood type AB be triggered by the presence of?
Neither A nor B
What do people with blood type O have?
Neither A nor B
What will the immune system of people with blood type O be triggered by the presence of?
A or B
What will the immune system of people with blood type A or B be triggered by the presence of?
The opposite antigen
What is the universal donor?
Blood type O because they can give to O, A, B, AB (can only receive from O)
What is the universal recipient?
Blood type AB because they can receive from O, A, B, AB (can only give to AB)
What can lipids be categorized as?
fats, oils, waxes and steroids
What does it mean that lipids contain many areas of hydrocarbons?
they have many areas of just hydrogen and carbon
What kind of covalent bond is between carbon and hydrogen?
non-polar covalent bond
What do the non-polar covalent bonds between carbon and hydrogen mean for lipids?
They dissolve well in non-polar solvents but not in water
What is a solution to the problem of lipid insolubility?
To conjugate the lipid with another molecule (ex. glycolipids, lipoproteins)
What are triglycerides?
Lipids that contain one glycerol molecule and three fatty acid molecules
How are lipids formed?
From condensation reactions
What are phospholipids?
When an inorganic phosphate group replaces one of the three fatty acids
What does each fatty acid always contain that is involved in the condensation reaction?
a terminal carboxyl group
How many carbons does glycerol have?
3
What are the three categories of fatty acids found within lipids?
Saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids
What are saturated fatty acids?
fatty acids that contain single bonds between the carbons
Why is the title “saturated fatty acids” what it is?
Because the molecule is saturated with hydrogens
What is the relative melting point of saturated fatty acids?
High
What state are saturated fatty acids in at room temperature?
solid
What are triglycerides containing only saturated fatty acids called?
“fats”
What are fats used for by animals?
to store excess energy
What are two examples of saturated fats?
fats in animal meat and butter
What are monounsaturated fatty acids?
fatty acids that have one double bond between two of the carbons in the hydrocarbon chain of the molecule
How does the melting point of triglycerides containing one or more monounsaturated fatty acids compare to saturated fatty acids?
The melting point is lower
What state are triglycerides containing one or more monounsaturated fatty acids in?
liquid (oil) at room temperature
What are polyunsaturated fatty acids?
fatty acids that have more than one double bond in the hydrocarbon chain
What is the relative melting point of triglycerides composed of polyunsaturated fatty acids?
relatively low
What state are triglycerides composed of polyunsaturated fatty acids in at room temperature?
liquid (oil)
What do animals/plants use to store energy in the form of?
saturated fatty acids: animals
monounsaturated fatty acids: some animals, many plants
polyunsaturated fatty acids: many plants
What is adipose tissue composed of?
cells that store fat in the form of triglycerides
What determines the quantity of triglycerides stored?
the organism’s caloric intake vs. the calories burned
When are condensation reactions that form triglycerides most common?
When an animal eats foods that have more calories than the organism is using
When do stored triglycerides undergo hydrolysis reactions?
When sufficient foods are not available for metabolic needs so the triglycerides are used to supply energy
What are the products of triglycerides that undergo hydrolysis reactions?
glycerol and fatty acids
Why are triglycerides useful for long-term energy storage?
Because they are insoluble in body fluids so they will not move from their adipose storage sites
Per gram of substance, approximately how much more energy do triglycerides provide compared to the energy released by carbohydrates?
2x
What is the thick adipose tissue on endotherms such as seals and walruses?
blubber found between their skin and muscles
What are amphipathic molecules?
molecules which have both hydrophilic and hydrophobic regions
What is an example of an amphipathic molecules?
phospholipids
Which end of the phospholipid is polar?
the end with the phosphate group
Which end of the phospholipid is non-polar?
the two long hydrocarbon tails
How do phospholipids solve the problem of having hydrophobic tails in an aqueous solution?
They form a bilayer (double layer)
What do the hydrophobic tails of phospholipids do in the bilayer?
they extend towards each other to keep away from the aqueous solutions inside and outside the cell
Why do the polar phosphate groups arrange themselves on the outside of the bilayer?
They are attracted to the aqueous solution
What is the bilayer of phospholipids the foundation of?
the plasma membrane
What are hormones?
chemical messenger molecules
What are hormones produced by?
a variety of glands in the body
What do hormones have access to?
All body tissues
What are steroids made from?
the lipid cholesterol
What is the fundamental structure of steroids?
4 hexagons
What are both oestradiol and testosterone produced by?
gonadal tissue
What are oestradiol and testosterone involved in the development of?
primary and secondary sex characteristics
Why can oestradiol and testosterone enter their target tissue cells?
Because they are soluble through the lipid bilayer of cells, and can directly enter through the plasma and nuclear membrane of the cell
What do hormones direct the process of once inside the nucleus of the cell?
transcription
