3 Chem of life (35/35) Flashcards
3.1.1 Sate that the most frequently occurring chemical elements in living things are ______, _____, _____ and ______.
the most frequently occurring chemical elements in living things are carbon, hydrogen, oxygen and nitrogen.
3.1.2 Sate thata variety of other elements are needed by living organisms, including _____, _______, _______, _____ and ______.
a variety of other elements are needed by living organisms, including sulfur, calcium, phosphorus, iron and sodium.
3.1.3 Sate one role for each of the elements mentioned in 3.1.2.
sulfur: Prokaryotes(chemical rxn involving sulfur as source of E), Plants+Animals(required to produce some of the amino acids that are part of enzymes they need)
phosphorus: Prokaryotes+Plants+Animals(all contain ATP and DNA, which contain phophorus)
calcium: Prokaryotes(maintaining cell structure and movement), Plants(component of cell walls and membranes), Animals(make out bones hard, lack causes osteoporosis, plays a role in releasing the neurotransmitter in the synapse when nerve messages are being transmitted)
iron: Prokaryotes(some anaerobic bacteria use a chemical rxn involving iron as their source of E), Plants(needed to hep the formation of chlorophyll), Animals(component of hemoglobin found in red blood cells; hemoglobin helps oxygen transport)
sodium: Prokaryotes(indirectly helps move the flagellum), Plants(in some plants sodium can help bind CO2 for photosynthesis), Animals(creating an action potential in neurons and aids glucose transport across membranes)
3.1.4 Draw and label water molecules to show their polarity and hydrogen bond formation.
do so
O -
/ \
H H + ~~ O -
/ \
H H3.1.5 Outline the thermal, cohesive and solvent properties of water.
thermal:
- high specific heat capacity: water requires a lot of energy to warm up and gives off a lot of energy when cooled down
-high heat of vaporization: water requires a lot of energy to change from a liquid to a gas
cohesive:
- the attraction forces between molecules of the same kind, strong in water molecules due
to H-bonds
solvent:
-water is polar and will dissolve many polar solutes “like dissolves like”
3.1.6 Explain the relationship between the properties of water and its uses in living organisms as a coolant, medium for metabolic reactions and transport medium.
thermal:
-use: transport: blood can carry heat to cooler regions
-use: coolant: plants/animals evaporate water which has a cooling effect - a little water will take lots of E to evaporate
cohesive:
-use: transport of water up the xylem of plants
solvent:
-use: transport in plants/animals is easier when molecules are dissolves, liquids are easier to transport: blood, xylem
-use: medium for metabolic rxns
3.2.1 Distinguish between organic and inorganic compounds.
Organic: are produced by living things and include all compounds containing CARBON (except: hydro carbonates, carbonates, oxides of carbon (CO, CO2)
Inorganic: all other compounds
3.2.2 Identify amino acids, glucose, ribose and fatty acids from diagrams showing their structure.
aa: central C atom, attatched to C: anmine group (NH2), carboxyll group (COOH), H group, R group(differs)
polypeptides: many aa, bonded together by peptide bonds
glucose: 6 carbons
ribose: 5 carbons
fatty a:carboxylic group
1 or more double bonds = unsaturated
no double bonds = saturated
see structures in book
3.2.3 List three examples each of monosaccharides, disccharides and polysaccharides.
monosaccharides: 1. glucose 2. fructose 3. galactose disccharides: 1. maltose 2. sucrose 3. lactose polysaccharides: 1. starch 2. glycogen 3. cellulose
3.2.4 Sate one function of glucose, lactose and glycogen in animals, and of fructose, sucrose and cellulose in plants.
Animals:
-glucose:source of E (respiration–>ATP)
-lactose: sugar found in milk, provide a source of E for babies
-glycogen: short term E storage in liver
Plants:
-fructose: sweet, good source of E
-sucrose: transport and storage of E
-cellulose: fibres, arranged in layers provide strength to cell wall
3.2.5 Outline the role of condensation and hydrolysis in the relationships between monosaccharides, disaccharides and polysaccharides; between fatty acids, glycerol and triglycerides; between amino acids and polypeptides.
Condensation: make complex
monosaccharide + monosaccharide –> disaccharide + water
Many monosaccharides or disaccharides –> polysaccharide + water
ex: glucose + glucose –> maltose + water
ex: glycerol + 3 fatty acids –> triglyceride + 3 water
Hydrolysis: make simpler
disaccharide + water –> monosaccharide +monosaccharide
polysaccharide + water –> Many monosaccharides or disaccharides
ex: sucrose + water –> glucose + fructose
ex: lactose + water –> glucose + galactose
3.2.6 Sate thee functions of lipids.
- energy storage
- thermal insulation
- main component of cell membrane (phospholipids)
3.2.7 Compare the use of carbohydrates and lipids in energy storage:
1g. lipid contains 2x as much E as 1g. carbohydrate (or protein) Lipids: -lipids needed for long term storage -light in weight (same amount of E in carbohydrates would weigh a lot more since more carbs would be needed) Carbohydrates: -short term energy storage between meals ANIMALS -L:long term -C:between meals PLANTS -L:immobile regions of plant (roots) -C:mobile, light weight (seeds)
3.3.1 Outline nucleotide structure in terms of sugar (deoxyribose), base and phosphate.
Deoxyribonucleic acid (DNA) is nucleic acid which is a long chain of molecules called nucleotides.
Nucleotides:
-pentose (5) sugar (deoxyribose)
-phosphate (H3PO4 forms 5 bonds with other atoms)
-organic base (nitrogen base: A, C, G or T)
~held together by covalent bonds
3.3.2 State the names of the four bases in DNA.
G - guanine
A - adenine
T - thymine
C - cytosine
EXTRA: PAIRS: ATU, CG ATU: form 2 H-bonds CG: form 3 H-bonds AG: purines (big 2 ring structures) CTU: pyrimidines (small 1 ring structures)
3.3.3 Outline how DNA nucleotides are linked togethr by covalent bonds into a single strand.
nucleotides are formed using condensation rxns: phosphate + sugar + base –> nucleotide + 2 water
linked together to form a single chain by a condensation rxn between the phosphate of one nucleotide and the sugar of another
backbone: phos covalently bonded to sugar ([deoxy]ribose) , bases stick out (attached to sugar)
3.3.4 Explain how a DNA double helix is formed using complementary base pairing and hydrogen bonds.
-nucleotide backbone (phosphate covalently
-bonded to pentose sugar(deoxyribose)
bases
-2 backbone strands run anti-parallel with nitrogen bases bonded in the middle
-to fill the middle space the organic bases have to combine to form 3 rings
-they need to form the same # of H-bonds
~A&T bond, C&G bond
-bonds between strands are H-bonds (weaker than covalent bonds)
3.3.5 Draw and label a simple diagram of the molecular structure of DNA.
do that :P
http://www.contexo.info/DNA_Basics/images/nucleotideHGPweb.gif
3.4.1 Explain DNA replication in terms of unwinding the double helix and separation of strands by helicase, followed by formation of the new complementary strands by DNA polymerase.
- DNA double helix unwinds/unzips: helicase
- free nucleotides in the nucleus form complementary base pairs w/ nucleotides on DNA
- DNA polymerase attaches the nucleotides to one another to create a new strand
- the old and the new strands join to form a new DNA helix
(more detes in HL)
3.4.2 Explain the significance of complimentary base paring in the conservation of the base sequence of DNA.
every organic base will only fit with one other base, the new DNA strand formed must be identical to the old strands complimentary strand.
replication can occur endlessly w/o change in DNA sequence theoretically
h/v mistakes called mutation occur
3.4.3 Sate that DNA replication is ________________.
DNA replication is semiconservative.
3.5.1 Compare the structure of RNA an DNA.
RNA:
- Shape: usually single stranded
- Sugar: ribose
- Bases: A,> U
- Shape: double helix (2 strands)
- Sugar: deoxyribose
- Bases: A,> T <, C, G
3.5.2 Outline transcription in terms of the formation of an RNA strand complementary on the DNA strand by RNA polymerase.
- Transcription: the process by which RNA is produced from DNA template
- takes place in the nucleus, involves DNA strand that needs to unzip
- 1 DNA strand(‘anti sense’) is transcribed –> 1 complimentary RNA strand made called mRNA/messenger RNA
- mRNA is identical (same nucleotide sequence) to ‘sense strand’ except T–>U (Uracil)
- after transcription mRNA leaves the nucleus through the nuclear pores in the nuclear membrane, into the cytoplasm
3.5.3 Describe the genetic code in terms of codons composed of triplets of bases.
codon: 3 nucleotides (4^3 = 64 different codons)
20 a.a.s are found in cells (>1 codon can code for an a.a.)
sequence of nucleotides, determines the system of codons, which determines the a.a. sequence in the polypeptide, which determines the type of protein that the polypeptide forms.
mRNA codon table is used to determine which codon codes for which a.a.
