B 1.1 Carbohydrates and lipids

why is carbon the foundation for all organic molecules?

covalent bonding

what is the carbon structure of fatty acids?

straight

what is the carbon structure of glycogen?

branched

what is the carbon structure of glucose?

ring structure

what are macromolecules?

large biological molecules made by joining monomers through a con

what is a condensation reaction?

chemical reactions in which 2 monomers bond by removing water → makes macromolecule or polymer

how does a condensation reaction work?

one monomer loses a (OH) hydroxyl group and the other loses a hydrogen

• water is then released and a new covalent bond forms between the monomers

what can a condensation reaction form?

polysaccharides (carbohydrate polymers), polypeptides (protein chains), nucleic acids

what type of bond does a condensation reaction make in polysaccharides?

glycosidic bond

what type of bond does a condensation reaction make in polypeptides?

peptide bond

what type of bond does a condensation reaction make in nucleic acids?

phosphodiester bond between phosphate of a nucleotide and a sugar of a different nucleotide

what are the monomers in polysaccharides?

glucose

what are the monomers in polypeptides?

amino acids

what are the monomers in nucleic acids?

phosphate and sugar

what is hydrolysis

the chemical breakdown of polymers into monomers using H2O

what is hydrolysis crucial for

food digestion, metabolism and nutrient absorption

what are monosaccharides

simplest form of carbohydrates, cannot by hydrolyzed into smaller sugars

what are examples of monosaccharides

• pentose, 5 carbon

• hexose, 6 carbon

both provide energy

why are monosaccharides important?

• small and soluble → easily moves through fluid

• provide energy →releases atp

• polymer precursor →forms starch, glycogen and cellulose

what is glucose

a monosaccharide → C6H12O6

what are the two types of glucose?

alpha and beta glucose

where is the hydroxyl group in an alpha glucose

on the bottom

where is the hydroxyl group in a beta glucose

on the top

what is alpha glucose used for?

glycogen and starch

what is beta glucose used for?

cellulose

what are the advantages of polysaccharides/ carbohydrate polymers

• coiled and branched structure → fits large energy in small space and has multiple ends for enzymes

• insoluble in water→ prevents osmosis swelling

• easily hydrolyzed → rapid glucose release for respiration

• no fixed size → can be as big or small as needed

how are glucose units used for energy storage?

• condensation reaction- a glucose is added to grow a polysaccharide

how are glucose units used for energy release?

hydrolysis reaction- breaks glycosidic bonds in polysaccharides to release glucose

what is starch

a type of polysaccharides used for energy storage in plants

what is starch made out of

amylose and amylopectin → alpha glucose

where is starch stored

• chloroplasts

• storage organs like seeds and tubers

what is the structure of amylose like?

coils/ helical structure of alpha glucose

what is the structure of amylopectin like?

branched chain of alpha glucose

what is glycogen

polysaccharide used for energy storage in animals

what is the structure of glycogen

• branches of amylopectin

• uses alpha glucose too

where is glycogen stored

liver and muscle cells

what is cellulose

structure polysaccharide used for plant cell walls

what is the structure of cellulose

• alternating beta glucose orientation in parallel chains

• hydrogen bonds between horizontal chains

what is the function of cellulose

• prevents cells from bursting due to osmotic intake

• maintains shape and rigidity in leaves stems and more

what is a glycoprotein

proteins with carbohydrate chains covalently attached

where are glycoproteins usually found?

cell membrane

what are glycoproteins used for?

cell identification, detection of pathogens, tissue compatibility, “cellular nametags”

what are lipids?

nonpolar biological molecules that are hydrophobic

what are lipids mainly composed of?

glycerol, fatty acids and a phosphate group

what are some examples of lipids

fats, oils, waxes and steroids

why are lipids hydrophobic

• nonpolar structure → lack charged region so water molecules are not attracted to them

• no hydrogen bonding

• tendency to cluster

what are triglycerides

type of lipid that has 1 glycerol and 3 fatty acids

• each fatty acid forms a covalent bond with glycerol using a condensation reaction

where are triglycerides stored

in the adipose tissue beneath the skin and around organs

what are triglycerides used for

long term energy storage

what are fatty acids

long hydrocarbon chains with a carboxyl group at the end

• building blocks of triglycerides and phospholipids

what do carbon bonds in fatty acids make

• kinks

• which releases intermolecular forces and lowers melting points

what do phospholipids do

make up the cell membrane

what is included in a phospholipid molecule

• 1 glycerol backbone

• 2 hydrophobic fatty acid tails

• 1 hydrophilic phosphate group

why are phospholipids important

• amphipathic nature drives spontaneous bilayer formation in water

• fluidity of the membrane allows embedded proteins and lipids to move

• semi permeability regulates transport of substances in/out of cell

what can steroids do because they are non polar

• can dissolve in the hydrophobic core of the membrane allowing:

• passing directly through the phospholipid bilayer

• enter target cells without target proteins

how do steroids work

• steroid hormones diffuse through bilayer

• in the cell they bind to intracellular receptors usually in the nucleus

• steroids can regulate gene expression by turning them on and off OR can trigger synthesis of specifc proteins

in what type of cell is starch found in

plant cells

what type of bonds does the starch amylose have

alpha glucose 1-4 glycosidic bond

what type of bonds does the starch amylopectin have

alpha glucose 1-6 and 1-4 glycosidic bond

what type of bonds does glycogen have

alpha 1-6, 1-4 glycosidic bond

what type of bonds does cellulose have

hydrogen bonds between chains vertically and beta glucose 1-4 glycosidic bonds