biochem

how many key biological molecules are vital to the human body?

5 key biological molecules

what are the 5 key biological molecules that are vital to the human body?

1. lipids (fat)
2. carbohydrates
3. proteins
4. nucleic acid
5. water

what are the 5 key biological molecules called?

polymers

which of the 5 key biological molecules is organic?

proteins, carbohydrates, lipids, nucleic acids

which of the 5 key biological molecules is inorganic?

water

what is the difference between inorganic and organic molecules?

organic = with C-atoms \n inorganic = no C-atoms

what are monomers?

building blocks of polymers (basic units)

What are the monomers of proteins?

amino acids

what are the monomers of carbohydrates?

monosaccharides

what are the monomers of lipids?

fatty acids and glycerol

what are the monomers of nucleic acids?

nucleotides

what are the monomers of water?

no monomer

What is a synthesis (dehydration) reaction?

process where biological monomers join together to form polymers (macromolecules) releasing water

What is a hydrolysis (digestion) reaction?

process where water is used to split a polymer into its monomers

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synthesis reaction

hydrolysis reaction

what is the biological purpose of proteins?

it is used in the body to build new tissues

what happens if proteins are in excess?

it is used to produce energy

what are the three main groups of each amino acid?

1. amine group/amine
2. carboxyl group/carboxylic acid
3. R (remainder) group

amino acid

amino group/amine

carboxyl group/carboxylic acid

R (remainder) group

how do each amino acid differ from each other?

in their R-group

how many different types of R-groups are there?

20 different R-groups

what is created when two amino acids synthesize?

dipeptide and water

name the type of bond that links amino acids together

peptide bond

what happens to the polymer of protein when water is added during hydrolysis?

it breaks down into many individual amino acids as water breaks down the peptide bond

exaplain the process

amino acids synthesized to form dipeptide as the amino acids are linked together by a peptide bond releasing water

what are the four categories of proteins

1. primary (1°) structure
2. secondary (2°) structure
3. tertiary (3°) structure
4. quaternary (4°) structure

what is the primary structure of a protein?

amino acids linked together in a linear fashion

primary structure protein

what is the secondary structure of a protein?

* polypeptide chain (1° structure) forms a long coil called alpha helix


* can also have beta-pleated sheets

secondary structure protein (alpha helix)

secondary structure protein (beta-pleated sheet)

what is the tertiary structure of a protein? what is it held together by?

* 2° structure folds on itself to form a globular structure
* held together by H-bonds, ionic bonds, etc

what also maintains this shape in 3° structure proteins?

attraction and repulsion of the R-groups also maintain this shape

what types of proteins are many tertiary structure proteins?

* functional proteins like hormones and enzymes
* structural proteins like hair, nails, skin

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tertiary structure protein

what is the quaternary structure of a protein?

2 or more secondary structure polypeptides interlink to form one large complex molecule

when a group is added to a protein it is called a….

prosthetic group - is a heme

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quaternary structure protein

what is denaturation?

process where the protein structure is disrupted

what factors can contribute to denaturation?

1. heat - curling iron to curl hair
2. acids - curdle milk
3. bases - perming or colouring hair

what does carbohydrates give your body?

energy

* it is the most readily available source of energy

what is the biological purpose of carbohydrates?

used to maintain blood sugar levels at 0.1% (homeostatic level)

what is it called when someone has a blood sugar level of less than 0.1%?

hypoglycemia

what is it called when someone has a blood sugar level of greater than 0.1%?

hyperglycemia aka diabetes

alpha-D-glucose

beta-D-glucose

what are the other monosaccharides and its source?

1. galactose (hexose) - milk
2. fructose (hexose) - fruits
3. ribose (pentose) - RNA/ATP
4. deoxyribose (pentose) - DNA

what is the empirical formula for carbohydrates?

CₙH₂ₙOₙ

name the type of bond that links monosaccharides together

glycosidic bond = ester bond

what is produced when tow monosaccharides are synthesized?

disaccharide and water

explain the process

two alpha glucose synthesize as they are held together by glycosidic bond forming a disaccharide (maltose) releasing water

what are other disaccharides?

1. sucrose = glucose + fructose
2. lactose = glucose + galactose

what are other carbohydrates (polysaccharides)?

1. starch
2. glycogen
3. cellulose

what is starch?

starch = a complex carbohydrate found in plant products

* storage form of glucose in plant
* branched polysaccharide

what is glycogen?

glycogen = storage form of glucose in animals

* more compact, easily stored
* stored in the liver and muscles of animals
* highly branched polysaccharide more so than starch

what is cellulose?

cellulose = found in plant cell walls

* very strong in nature
* very fibrous (fibre)
* undigestible by humans because we lack enzymes called cellulase to break it down
* unique structure as glycosidic bond

cellulose unique structure as glycosidic bond

what are the three main types of lipids?

1. neutral fats
2. steroids
3. phospholipids

what are neutral fats?

neutral fats = fats and oils

* heat insulation
* long term energy storage
* protective cushioning

what are steroids?

steroids = lipids with a backbone of 4 fused carbon rings

* eg. cholesterol, testosterone, estrogen, progesterone

where are phospholipids found?

phospholipids = found in cell membranes

what are the basic units of neutral fats?

3 fatty acids and 1 glycerol

* aka triglyceride

what is the structure of fatty acids?

long chain of carbon and hydrogen

what do fatty acids and amino aids have in common?

carboxylic acid

how many carbons are there usually per fatty acid?

16 or 18 carbons

fatty acid

polyunsaturated fatty acid

monounsaturated fatty acid

what are the two types of fatty acids?

1. saturated fatty acid
2. unsaturated fatty acid

what are saturated fatty acids? examples?

* animal products
* saturated with lots of hydrogen atoms
* no double bond betw. C and H
* usually solid at room/body temp.

eg. red meats, butter, cheese, palm oil, coconut oil

what are unsaturated fatty acids? examples?

* there are several double bonds between carbon atoms (not as many carbon atoms)
* found in plant products
* usually liquid at room/body temp

eg. corn oil, canola oil, olive oil, fish (omega-3)

omega-3

glycerol

3 fatty acids (saturated) + 1 glycerol → triglyceride (neutral fat) + _H₂O

what bond is used in a triglyceride?

ester bond

what are monounsaturated fat?

with one double bond

what are polyunsaturated fat?

more than one double bond (better)

what makes a phospholipid?

one of the fatty acids is replaced by a phosphate group

phospholipids

abbreviated phospholipids

where are nucleic acids found?

found in cells (esp. in nucleus) -- genetic material or energy molecules

what are the three types of nucleic acid?

1. DNA - deoxyribonucleic acid (genetic material)
2. RNA - ribonucleic acid (genetic material)
3. ATP - adenosine triphosphate (energy)

is water polar or nonpolar? explain

polar (partial positive and negative charges - unequal sharing of electrons)

* attracts other molecules (essential for transport)

what type of bonding does water have?

1. hydrogen bonding (intermolecular)
2. covalent bonding (intramolecular)

hydrogen bonding (intermolecular)

covalent bonding (intramolecular)

* unequal sharing of electrons between H + O atoms

what does it mean when water has weak attraction between water molecules?

water has some special properties

what are the properties of water?

1. universal solvent
2. temperature regulator
3. lubricant

how is water a universal solvent? examples?

* b/c water is polar, it can dissociate or dissolve ionic compounds into separate ions
* dissolves other polar molecules like sugar and alcohol
* crucial for life to separate ions

eg. potassium (nerve conduction)

sodium, calcium (nerve + muscle conduction)

how is water temperature regulator?

* water has high specific heat/heat capacity
* takes a great amount of nrg to heat water 1°C
* therefore, water buffers changes in temp.
* helps keep body temp. @37°C (cooling effect of sweating)

how is water a lubricant?

reduces friction between 2 surfaces

eg. joints - synovial fluids

although water is a covalent molecule, it occasionally dissociates into ions

how are the ions in pure water?

H and OH ions are balanced

what is the pH of pure water?

pH 7 (neutral)

what is the pH of blood?

pH 7.4

what is the relation between pH + living organisms?

* biological systems are extremely sensitive to pH
* biochemical molecules (proteins can change structure - denature - with even small changes in pH
* enzymes (proteins) functions best within narrow pH range