©Themoon EXAM SOLUTIONS
25/11/2024 09:27AM
BIOS 201 Fall Semester All Terms Questions
and Answers
How do biological molecules come together? 8/24 - Answers✓✓Bonding:
Hydrogen bonding (polar bonds due to differences in electronegativity)
Covalent bonding (can be either polar or nonpolar, strongest type of bond)
covalent bonds - Answers✓✓Bonds created by sharing electrons with other atoms. (strongest
type of bond)
hydrogen bonds - Answers✓✓attractive forces in which a hydrogen covalently bonded to a
very electronegative atom is also weakly bonded to an unshared electron pair of another
electronegative atom (best example is H2O or water)
Hydrophobic interactions - Answers✓✓a type of weak chemical interaction caused when
molecules that do not mix with water coalesce to exclude water
commonly found in phospholipid bilayer in the cell membrane to keep non-water soluble items
out of the cell
How do macromolecules such as proteins, polysaccharides, and nucleic acids each form
specific 3D structures? 8/26 - Answers✓✓covalent bonds and non-covalent bonds that are
formed through synthesis (really dehydration synthesis), and they are dissembled through
hydrolysis/depolymerize/degrade
non-covalent bonds - Answers✓✓1. hydrophobic interactions
2. hydrogen bonds
, ©Themoon EXAM SOLUTIONS
25/11/2024 09:27AM
3. ionic interactions (electrostatic interactions between positively and negatively charged ions)
4. ionic bond (donation/acceptance of electrons as bond)
polysaccharide structure - Answers✓✓-polymer of monosaccharides joined by synthesis and
the formation of water
-glycogen is an important storage molecule due to extensive branching with free ends for
hydrolysis (to be broken down and used for energy)
-both alpha and beta rings are formed
polysaccharide function - Answers✓✓energy storage (glycogen and starch) and structural
support (cellulose in plants)
lipid structure - Answers✓✓composed of 3 fatty acids and 1 glycerol molecule (called
triglyceride/triacylglycerol for this reason that are joined by an ester linkage)
hydrophobic (phospholipids are found in cell membranes due to polarized/unpolarized ends)
can also be a carbon skeleton with fused rings (steroids)
lipid function - Answers✓✓fats --> long term, compact energy storage
phospholipids --> cell membrane regulation due to hydrophilic/hydrophobic ends
steroids --> formed from cholesterol for hormones (especially vertebrae sex hormones)
protein structure (6 things) - Answers✓✓a. Long chains of amino acids
b. Joined to each other by peptide bonds
c. Structure of each protein dictated by DNA of a gene
d. can be formed into secondary structures through hydrogen bonds which allow them to fold
onto each other (often dictated by protein's specific function, ex. store hemoglobin)
, ©Themoon EXAM SOLUTIONS
25/11/2024 09:27AM
e. each group has an amino group (-NH2) and a carboxyl group/acid (-COOH), both of which
are polar
f. side chain dictates the type of amino acid is formed
Amino Acid into Protein Synthesis - Answers✓✓the N-terminus side is put together first while
the C-terminus is at the end
nucleic acid structure - Answers✓✓-Chain of nucleotides that consists of a pentose
(deoxyribose or ribose), a phosphate group, and a nitrogenous base (either pyrimidine - TCU,
or purine - AG)
-two types: DNA (double-helix with AT/GC) and RNA (single-helix with AU/GC)
-phosphate that links sugar with phosphodiester linkages make up the sugar-phosphate
backbone
ATP function - Answers✓✓-transfer of energy by breaking and synthesizing a third phosphate
group onto ADP (adenine diphosphate)
-main method to convert energy from food/light energy to usable energy for the cell
-yields energy when catabolizes (exergonic) before anabolizes (endergonic) and builds back up
-acts as an immediate source of energy that powers cellular work
exergonic-endergonic reaction coupling - Answers✓✓-exergonic reactions proceed with net
release of free energy (ATP --> ADP)
-endergonic reactions absorb free energy from its surroundings (ADP --> ATP)
-cells use the exergonic process to drive the endergonic one
How are proteins folded into native shapes inside cells? 8/28 - Answers✓✓1. polypeptides are
formed from mRNA in the site of ribosomes
, ©Themoon EXAM SOLUTIONS
25/11/2024 09:27AM
2. as the polypeptides are formed, the hydrophobic amino acids collapse
3. the protein HSP 70 Chaperone (powered by ATP hydrolysis) tries to hold the nonpolar
regions from deforming for a little bit while they are being made (if this process works
successfully, then go to step 6, if not then go to step 4 [70ish% are incorrect] )
4. ubiquitin (UBI) ligase recognizes it and puts a tag -UBI- on the polypeptide
5. ubiquitin (UBI) will covalently bond with the unfolded amino acids before a proteasome
breaks down the polypeptide into smaller chunks which are then used for the immune system
6. either an alpha helix (helix-shaped) or beta sheet (sheet-shaped) is formed based on the
permissiveness of side chains (whether or not they got in the way)
Chaperones - protein folding in cells - Answers✓✓proteins which help regulate the folding
process for proteins, leading them to be in the correct functional state for that particular
protein's function
HSP 70 helps with folding
Protein turnover in cells via ubiquitin-proteasome system - Answers✓✓for proteins that did not
fold correctly (even after the HSP 70 Chaperone tried to fix it), then the ubiquitin-ligase
enzyme tags the faulty protein by covalently bonding ubiquitin with the faulty protein
Then the proteasome processes the tagged faulty protein and breaks it up into smaller
polypeptides/amino acid chains to be used by the immune system
How do enzymes catalyze chemical reactions and how is enzyme activity regulated? Textbook
answer 8/31 - Answers✓✓enzymes help speed up chemical reactions by helping to break up
ATP into ADP and P_i and also lower the necessary activation energy to start the reaction
enzyme activity is regulated through allosteric regulation (protein's function at one site is
affected by binding of regulatory molecule to a separate site) and inhibition (disallowing the
units to bind to the active sites by binding to them instead)
25/11/2024 09:27AM
BIOS 201 Fall Semester All Terms Questions
and Answers
How do biological molecules come together? 8/24 - Answers✓✓Bonding:
Hydrogen bonding (polar bonds due to differences in electronegativity)
Covalent bonding (can be either polar or nonpolar, strongest type of bond)
covalent bonds - Answers✓✓Bonds created by sharing electrons with other atoms. (strongest
type of bond)
hydrogen bonds - Answers✓✓attractive forces in which a hydrogen covalently bonded to a
very electronegative atom is also weakly bonded to an unshared electron pair of another
electronegative atom (best example is H2O or water)
Hydrophobic interactions - Answers✓✓a type of weak chemical interaction caused when
molecules that do not mix with water coalesce to exclude water
commonly found in phospholipid bilayer in the cell membrane to keep non-water soluble items
out of the cell
How do macromolecules such as proteins, polysaccharides, and nucleic acids each form
specific 3D structures? 8/26 - Answers✓✓covalent bonds and non-covalent bonds that are
formed through synthesis (really dehydration synthesis), and they are dissembled through
hydrolysis/depolymerize/degrade
non-covalent bonds - Answers✓✓1. hydrophobic interactions
2. hydrogen bonds
, ©Themoon EXAM SOLUTIONS
25/11/2024 09:27AM
3. ionic interactions (electrostatic interactions between positively and negatively charged ions)
4. ionic bond (donation/acceptance of electrons as bond)
polysaccharide structure - Answers✓✓-polymer of monosaccharides joined by synthesis and
the formation of water
-glycogen is an important storage molecule due to extensive branching with free ends for
hydrolysis (to be broken down and used for energy)
-both alpha and beta rings are formed
polysaccharide function - Answers✓✓energy storage (glycogen and starch) and structural
support (cellulose in plants)
lipid structure - Answers✓✓composed of 3 fatty acids and 1 glycerol molecule (called
triglyceride/triacylglycerol for this reason that are joined by an ester linkage)
hydrophobic (phospholipids are found in cell membranes due to polarized/unpolarized ends)
can also be a carbon skeleton with fused rings (steroids)
lipid function - Answers✓✓fats --> long term, compact energy storage
phospholipids --> cell membrane regulation due to hydrophilic/hydrophobic ends
steroids --> formed from cholesterol for hormones (especially vertebrae sex hormones)
protein structure (6 things) - Answers✓✓a. Long chains of amino acids
b. Joined to each other by peptide bonds
c. Structure of each protein dictated by DNA of a gene
d. can be formed into secondary structures through hydrogen bonds which allow them to fold
onto each other (often dictated by protein's specific function, ex. store hemoglobin)
, ©Themoon EXAM SOLUTIONS
25/11/2024 09:27AM
e. each group has an amino group (-NH2) and a carboxyl group/acid (-COOH), both of which
are polar
f. side chain dictates the type of amino acid is formed
Amino Acid into Protein Synthesis - Answers✓✓the N-terminus side is put together first while
the C-terminus is at the end
nucleic acid structure - Answers✓✓-Chain of nucleotides that consists of a pentose
(deoxyribose or ribose), a phosphate group, and a nitrogenous base (either pyrimidine - TCU,
or purine - AG)
-two types: DNA (double-helix with AT/GC) and RNA (single-helix with AU/GC)
-phosphate that links sugar with phosphodiester linkages make up the sugar-phosphate
backbone
ATP function - Answers✓✓-transfer of energy by breaking and synthesizing a third phosphate
group onto ADP (adenine diphosphate)
-main method to convert energy from food/light energy to usable energy for the cell
-yields energy when catabolizes (exergonic) before anabolizes (endergonic) and builds back up
-acts as an immediate source of energy that powers cellular work
exergonic-endergonic reaction coupling - Answers✓✓-exergonic reactions proceed with net
release of free energy (ATP --> ADP)
-endergonic reactions absorb free energy from its surroundings (ADP --> ATP)
-cells use the exergonic process to drive the endergonic one
How are proteins folded into native shapes inside cells? 8/28 - Answers✓✓1. polypeptides are
formed from mRNA in the site of ribosomes
, ©Themoon EXAM SOLUTIONS
25/11/2024 09:27AM
2. as the polypeptides are formed, the hydrophobic amino acids collapse
3. the protein HSP 70 Chaperone (powered by ATP hydrolysis) tries to hold the nonpolar
regions from deforming for a little bit while they are being made (if this process works
successfully, then go to step 6, if not then go to step 4 [70ish% are incorrect] )
4. ubiquitin (UBI) ligase recognizes it and puts a tag -UBI- on the polypeptide
5. ubiquitin (UBI) will covalently bond with the unfolded amino acids before a proteasome
breaks down the polypeptide into smaller chunks which are then used for the immune system
6. either an alpha helix (helix-shaped) or beta sheet (sheet-shaped) is formed based on the
permissiveness of side chains (whether or not they got in the way)
Chaperones - protein folding in cells - Answers✓✓proteins which help regulate the folding
process for proteins, leading them to be in the correct functional state for that particular
protein's function
HSP 70 helps with folding
Protein turnover in cells via ubiquitin-proteasome system - Answers✓✓for proteins that did not
fold correctly (even after the HSP 70 Chaperone tried to fix it), then the ubiquitin-ligase
enzyme tags the faulty protein by covalently bonding ubiquitin with the faulty protein
Then the proteasome processes the tagged faulty protein and breaks it up into smaller
polypeptides/amino acid chains to be used by the immune system
How do enzymes catalyze chemical reactions and how is enzyme activity regulated? Textbook
answer 8/31 - Answers✓✓enzymes help speed up chemical reactions by helping to break up
ATP into ADP and P_i and also lower the necessary activation energy to start the reaction
enzyme activity is regulated through allosteric regulation (protein's function at one site is
affected by binding of regulatory molecule to a separate site) and inhibition (disallowing the
units to bind to the active sites by binding to them instead)
