Ch. 3 Molecules of Life Flashcards
organic
compounds that mainly consist of carbon and hydrogen
non-organic
molecules that have no carbon atoms
ex. water
Why study carbon?
Carbon’s outer shell has only 4 electrons which allows carbon to make pretty stable covalent bonds with other elements
How do carbon atoms bond?
3-dimensionally
hydrocarbon
carbon chain with only hydrogen attached, completely non-polar
carbon bonds
- single
- double
- triple
Single carbon bonds
rotates easily
ex. single bonded straight carbon chain:
H H H H
H-C-C-C-C-H
H H H Hdouble carbon bonds
moderate movement
ex. double bonded carbon chain:
H H
C=C
H Htriple carbon bonds
restricted movement
ex. triple bond
H- C≡C-H
branched carbon chain
H H H H
H-C-C-C-C-H
H H | H
H -C -H
ringed carbon chain
example:
H
H C H
C C
C C
H C H
H
functional groups
an atom (other than hydrogen) or small molecular group that covalently bonds to the carbon backbone of an organic compound ex. carboxyl group
What do functional groups do?
functional groups give organisms it its different structure and function
ex. estrogen and testostorone
Types of metabolic reactions (that we’ll study most)
- condensation
- hydrolysis (cleavage)
condensation reaction
2 molecules covalently combine to form a larger molecule by addition of heat and release of water
subunits=polymer
A+B=AB
hydrolysis (cleavage) reaction
a large molecule splits into two smaller molecules by addition of water
polymer=-subunits
AB=A+B
Macromolecules
- carbohydrates
- lipids
- proteins
- nucleic acids
What are carbohydrates?
most abundant of all biological molecules
- structure: C,H,O in a 1:2:1 ratio
uses: structural material, stored energy, transportable energy
Types of carbohydrates
- monosaccharides
- disaccharides
- polysaccharides
Monosaccharides
(simple sugars) simplest carbohydrates - are the main energy source for most organisms -sweet tasting, water soluble -most have 5- or 6- carbon backbone
examples of monosaccharides
glucose (6C)
fructose (5C)
ribose (5C)
deoxyribose (5C)
Disaccharides
(double sugar)
- *short chain carbohydrates**
- formed by condensation reaction
examples of disaccharides
lactose, maltose, and (sucrose- most plentiful in nature)
*glucose+fructose=sucrose**
Polysaccharides
(complex sugars)
- straight/ branched chains of many sugar monomers (3+)
- -composed entirely of glucose
examples of polysaccharides
cellulose (tough, indigestible plant fibers: celery)
starch (amylose in grains, potato and pasta)
*takes longer to digest
chitin: forms external skeleton/ hard body parts in many animals (ex. crabs, earthworms, insects, ticks) **also found in fungi
glycogen
sugar storage polysaccharide molecule in muscles and liver of animals
- only sugar storing molecules in animals*
- can be broken into glucose when blood sugar drops*
Lipids
(fats)
structure: a glycerol with 1,2, or 3 fatty acid tails
- doesn’t dissolve easily in water; also hydrophobic and non-polar
uses: cell membrane structure, energy storage, signal molecules, water proofing covering
examples of lipids
- saturated fats
- monounsaturated
- polyunsaturated
- triglycerides
- waxes
- sterols
lipids and fatty acid types
-with fatty acid tail:
fats/triglycerides, phospholipid, waxes, saturated,
monounsaturated, polyunsaturated
-no fatty acid tail:
sterols
Saturated fats
(single bonded only)
- solid at room temperature
- don’t break down easily; fully saturated with hydrogen
ex. beef fat, pork fat, lard, butter
Monounsaturated fats
(carbon chain has 1 or more double bonds)
- liquid at room temperature
- breaks down easier; not fully saturated with hydrogens
ex. olive oil, cheese, nuts, eggs
Polyunsaturated fats
(carbon chain with at least 3 double bonds)
- best for your health: easier to digest
ex. seeds, soybeans, avocado
Triglycerides
consists of a glycerol and 3 fatty acid tails
- neutral fat -most abundant lipid in human body
- richest energy source (9cal/gm)
uses: insulation, fat storage, protection of bones and internal organs
Phospolipids
consists of a glycerol with a phosphate head and 2 fatty acid tails
-creates the phospholipid bilayer in the cell
- maintains homeostasis in the cell: regulates what
enters/exists the cell
Waxes
- firm consistency: repel water
- waterproofing in plants/animals
ex. cuticles on fruit, veggies, leaves; beeswax, earwax, skin, hair, feathers
dessication
action of drying, removal of moisture
Sterols
(lipids with no fatty acid tail)
- four carbon ring with functional groups
- regulates hormone and vitamin production
ex. cholesterol, hormones, steroids, bile salts, vitaminD
cholesterol
most common sterol in animals (made by liver) and obtained through diet
-too much can lead to atherosclerosis
atherosclerosis
not that important to know completely
deposits of plaque (fatty material) on the walls of blood vessel that constricts the flow of blood through the veins and arteries– can lead to heart disease
sterols and hormones
give rise to secondary sexual characteristics and gamete formation
ex. estrogen and testosterone
Proteins (pt1)
chain of amino acids held by/linked together by peptide bonds (called a polypeptide)
- proteins determine the structure and functions of organisms
- *20 different kinds of amino acids make up 100 million particles
Proteins (pt2)
structure dictations function:
- 3 dimensional shape of protein determines its biological function
- primary structure
- secondary structure
- tertiary structure
- quaternary structure
primary structure
linear chain of amino acids (polypeptide)*type of protein
-[]-[]-[]-[]-[]-[]-[]
secondary structure
polypeptide folds in helices/folded sheets
/\/\/\/\/\/\/\/\/\/\/\
/\/\/\/\/\/\/\/\/\/\/\
tertiary structure
further folding of helices or sheet into loop
-these sheets make a protein a “working molecule”
quaternary structure
two or more polypeptide held into a globule for a particular shapes for a specific function
fibrous protein
chains arranged as strands or sheets
ex. keratin, collagen
major types of proteins
- structural
- regulatory
- hormones
- transport
- antigens
- enzymes
structural proteins
make up cell parts, keratin in skin and hair, feathers, webs, bones and cartilage
regulatory proteins
controls the individual parts of cell (organelles)
hormone proteins
“molecular messages” that control growth and developement
transport proteins
carry substances throughout body
ex. hemoglobin
antigen proteins
cause formation of antibodies which provide protection from disease
*specific to their antigen
enzyme protein
special proteins that act as a catalyst to speed up reactions
polypeptides may have organic compounds attached like:
- lipoproteins: proteins combined with lipids/fats
- glycoproteins: proteins combined with sugars
denaturation
disruption of 3 dimensional shape of a protein
- will cause a protein to no longer function properly
- causes of denaturation: pH, temperature
Nucleic acids
(DNA or RNA) rna- single coil (ribose sugar) dna- double coil (deoxyribose sugar) -both consist of nucleotides (sugar, phosphate, and nitrogen base
nitrogen bases
purines: adenine or guanine
*double unit
pyrimidines: thymine or cytosine
*single unit
(thymine is replaced by purine: uracil in RNA)
purine and pyrimidines
purines join with pyrimidines to joint the two sides of DNA molecules in the following order ONLY:
A-T
G-C
