Building a cell (p2) Flashcards
Macromolecules
- Polymers composed of monomers that are linked together by covalent bonds
To exchange atoms and form macromolecules:
- Molecules must be moving/collide which can’t happen at absolute 0
Dehydration Synthesis
- Water is a product
- Monomer -> Dimer
- Forms COVALENT bonds, releases water
- Slow reactions
Hydrolysis
- Water is a reactant
- Breaks down Dimers and Polymers
- Breaks bonds, water is formed and energy often released
How to speed up the process of making/breaking down Macromolecules
- increase concentration of monomer to cause collision
- increase temp to increase motion & collisions
- IN CELLS: Enzymes - bc they control concentration of monomers and the temp
Carbs (CH2O)n
- COVALENTLY bonded
Monosaccharides
Simplest form of carb
- Glyceraldehyde (triose) - base of many reactions that lead to ATP
- Ribose (pentose)
- Glucose (hexose)
Disaccharides
Sucrose (glucose + fructose)
- Held together by GLYCOSIDIC bonds (need special enzyme to break and form this bond)
Polysaccharides
- Dense structures (Ex. Glycogen)
- Enzymes form them out of sugar subunits
- Store monosaccharides for energy
- Structure is BRANCHED (Glycogen, Amylopectin) or UNBRANCHED (Starch)
- Form rigid biological structures like cellulose and chitin
Cellulose
- Formed by H-bonds
-> So it can be easily broken down with the right enzyme that digests cellulose and break H-bond systems
Lipids
- Fats (used for metabolism)
- Steroids (form vitamins/hormones)
- Phospholipids (form cell membranes)
Fats
- Used for Metabolism
- Glycerol + fatty acid
- No charge
- More bonds = more stored energy
Types of Fats
- Saturated fatty acid
-> No double bonds, solid at room temp - Unsaturated trans
-> H-atoms opposite side, semi-solid at room temp
-> Bonds aren’t saturated with Hydrogen
-> Collect in bloodstream as clumps - Unsaturated cis
-> H-atoms on same side, liquid at room temp
-> Bent configuration = more flexible, better for health
-> MONO = one double bond
-> POLY = multiple double bonds, more bent
Phospholipids
- Amphipathic molecules (Hydrophobic head, Hydrophilic tail)
-> form cell membranes & keep water out of membrane - Composed of saturated/unsaturated fats
- Phospholipids had to evolve first before cells
Steroids
Cholesterol is a precursor for the synthesis of hormones and vitamin
Amino acids & Polypeptides
- Amino acids form polypeptides.
- Amino acids are linked with PEPTIDE BONDS (Covalent)
-> Dehydration synthesis forms PEPTIDE BONDS - Amino acids - monomer/subunit
- Amino acids have: Amino group (NH4) + Carboxyl group (COOH)
Nonpolar Amino acids
- Hydrocarbon side chain
-> Other than Glycine: has Hydrogen side chain
Polar Amino acids
- Net (+/-) or partial (uncharged) sidecahins
Electrically charged Amino acids
- Either very attractive or very repulsive, impacting whether amino acids accepts or released H+
-> Accepts H+, env. = more acidic = neg charge
-> Releases H+, env. = more basic = pos charge
Primary structure
Polypeptide is a polymer of amino acids (sequence of amino acids)
Secondary structure
- Helix or Pleated sheet
-> Formed by H-bonding along amino acid chain - How it folds
Tertiary structure
- 3D folding of polypeptide chain bc of interactions from distant amino acids
- Ex. Globin
Quaternary structure
- Multiple proteins (folded polypeptide chains) form one protein
- Ex. Hemoglobin (in RBC, transport Oxygen)
Minimal Energy State
When entire protein is fully stable and has fully folded
A change in one amino acid changes protein structure
- Missense mutation in Hemoglobin causes SICKLE CELL ANEMIA
- 1 normal Hemoglobin gene + mutation = protection from Malaria
- 2 normal Hemoglobin genes + mutation = SICKLE CELL ANEMIA
Silent Mutations
- Protein does not change shape
- If you have a mutation in the 3rd nucleotide of the amino acid
Missense Mutations
- Function of protein might change
- Could change things if you go from acidic to basic or uncharged to changed
Nonsense Mutations
- Protein truncated, loss of function
- Changes a regular codon into a stop codon
Frameshift mutations
- Different protein, or a truncated protein
- Loss or Gain of function
- Such mutations are the cause of many diseases
- DNA sequence read from 5’ to 3’, so everything past that mutation will be wrong: lost or a different sequence
Which of these properties of liquid water make it an excellent solvent for living cells: (select one)
Solvent: any substance, usually liquid, which is capable of dissolving one or several substances, thus creating a solution. (interacts with other substances)
a) Water is an angry vindictive atom
b) Water molecules form ionic bonds with each other
c) Hydrogen bonds between water molecules break and form randomly
d) Water has a low heat vaporization
e) Polar covalent bonds within water molecules break and form randomly
Hydrogen bonds between water molecules break and form randomly
When a polypeptide folds into a protein, which type of bond between H and O atoms would be expected to form?
H-bond
The rate of synthesis of a polysaccharide can be influenced by:
a) Temperature
b) The concentration of fatty acids
c) The presence of an enzyme
d) Rabbits
e) The concentration of monosaccharides
Temperature, presence of an enzyme, concentration of monosaccharides
How does C=C cis double covalent bond affect the shape of a phospholipid
a) It increases the length of the hydrocarbon tails
b) It increases the number of hydrocarbon tails
c) It bends a hydrocarbon tail
d) It straightens a hydrocarbon tail
e) It increases the number of mixed martial arts fights that occur in the membrane
c) It bends a hydrocarbon tail
