BS 161 FINAL EXAM LATEST 2024-2025
QUESTIONS AND CORRECT ANSWERS
GRADED A+
Compare and contrast the strength of each interaction in a solid versus an
aqueous solution. - ANSWER-Solid has higher concentration of bonds than
aqueous solution
why water is able to form hydrogen bonds - ANSWER-they have polar covalent
bonds and the partially positive hydrogen bonds to other partially negative
oxygens
why polar and charged species dissolve in water - ANSWER-molecules that have
partially positive and partially negative areas are polar and can be dissolved in
water
water can attract charged particles because it has partially positive and negative
areas and if the attractions between the ions and water are stronger than
attractions between ions it will dissolve in water
,bonds between solute compound are disrupted in order to increase bond length
and allow aqueous solution to flow through
why oil will not dissolve in water - ANSWER-water is polar and oil is nonpolar so
their molecules do not attract each other
List the common functions of proteins in cells - ANSWER-energy storage,
structural support, transport, messengers, enzyme catalyst etc.
Describe four levels of protein structure and identify common representations -
ANSWER-Primary- amino acid chain
Secondary- alpha helix beta pleated sheets
Tertiary- proteins or polypeptides
Quaternary- multiple polypeptides
Define a lipid. - ANSWER-Insoluble in water and soluble in organic substances
Draw the difference between saturated and unsaturated fats - ANSWER-
Unsaturated has double bonds, and saturated has a carbon bonded to at least 2
hydrogens
,Explain the difference between solid fats and liquid oils on a molecular level. -
ANSWER-Solid fats have more hydrogens, the more hydrogens there are the more
concentrated it is therefore the more solid it is
Define a biological membrane. - ANSWER-Selectively permeable barrier between
living things
Describe the fluid mosaic model of membrane structure. - ANSWER-Different
transport proteins that allow ions to be diffused through a bilayer
Describe difference between peripheral and integral membrane proteins. -
ANSWER-Integral proteins are on the inside and nonpolar regions of membranes
of hydrophobic layer and peripheral proteins are on the surface and it is on
mitochondria and chloroplasts
List six major functions of membrane proteins. - ANSWER-Transporters enzymes-
carry out chemical reactions
cell surface receptors- detect chemical messages and anchors to surface
cell surface id receptors
cell to cell adhesion proteins
, cytoskeleton proteins
Explain why the lipid bilayer of a biological membrane forms spontaneously. -
ANSWER-Doesn't need outside source of energy to form
Explain the meaning of the statement "Phospholipids and most other membrane
constituents (e.g., proteins) are amphipathic molecules." - ANSWER-Phospholipids
are both hydrophobic and hydrophilic
Explain how membrane fluidity is influenced by temperature. - ANSWER-lower
temperature higher fluidity- unsaturated fats
Explain how cholesterol resists changes in membrane fluidity as temperatures
change. - ANSWER-At moderate temperature, reduces fluidity bc reduces
phospholipid movement
At lower temperature, stops solidification
Explain the role of membrane carbohydrates in cell-cell recognition. - ANSWER-
Bond to lipids or proteins, function as markers to distinguish from one another
Explain how the polarity of a molecule affects how it moves across a membrane. -
ANSWER-Nonpolar can move across membrane, polar can't without carrier
protein
QUESTIONS AND CORRECT ANSWERS
GRADED A+
Compare and contrast the strength of each interaction in a solid versus an
aqueous solution. - ANSWER-Solid has higher concentration of bonds than
aqueous solution
why water is able to form hydrogen bonds - ANSWER-they have polar covalent
bonds and the partially positive hydrogen bonds to other partially negative
oxygens
why polar and charged species dissolve in water - ANSWER-molecules that have
partially positive and partially negative areas are polar and can be dissolved in
water
water can attract charged particles because it has partially positive and negative
areas and if the attractions between the ions and water are stronger than
attractions between ions it will dissolve in water
,bonds between solute compound are disrupted in order to increase bond length
and allow aqueous solution to flow through
why oil will not dissolve in water - ANSWER-water is polar and oil is nonpolar so
their molecules do not attract each other
List the common functions of proteins in cells - ANSWER-energy storage,
structural support, transport, messengers, enzyme catalyst etc.
Describe four levels of protein structure and identify common representations -
ANSWER-Primary- amino acid chain
Secondary- alpha helix beta pleated sheets
Tertiary- proteins or polypeptides
Quaternary- multiple polypeptides
Define a lipid. - ANSWER-Insoluble in water and soluble in organic substances
Draw the difference between saturated and unsaturated fats - ANSWER-
Unsaturated has double bonds, and saturated has a carbon bonded to at least 2
hydrogens
,Explain the difference between solid fats and liquid oils on a molecular level. -
ANSWER-Solid fats have more hydrogens, the more hydrogens there are the more
concentrated it is therefore the more solid it is
Define a biological membrane. - ANSWER-Selectively permeable barrier between
living things
Describe the fluid mosaic model of membrane structure. - ANSWER-Different
transport proteins that allow ions to be diffused through a bilayer
Describe difference between peripheral and integral membrane proteins. -
ANSWER-Integral proteins are on the inside and nonpolar regions of membranes
of hydrophobic layer and peripheral proteins are on the surface and it is on
mitochondria and chloroplasts
List six major functions of membrane proteins. - ANSWER-Transporters enzymes-
carry out chemical reactions
cell surface receptors- detect chemical messages and anchors to surface
cell surface id receptors
cell to cell adhesion proteins
, cytoskeleton proteins
Explain why the lipid bilayer of a biological membrane forms spontaneously. -
ANSWER-Doesn't need outside source of energy to form
Explain the meaning of the statement "Phospholipids and most other membrane
constituents (e.g., proteins) are amphipathic molecules." - ANSWER-Phospholipids
are both hydrophobic and hydrophilic
Explain how membrane fluidity is influenced by temperature. - ANSWER-lower
temperature higher fluidity- unsaturated fats
Explain how cholesterol resists changes in membrane fluidity as temperatures
change. - ANSWER-At moderate temperature, reduces fluidity bc reduces
phospholipid movement
At lower temperature, stops solidification
Explain the role of membrane carbohydrates in cell-cell recognition. - ANSWER-
Bond to lipids or proteins, function as markers to distinguish from one another
Explain how the polarity of a molecule affects how it moves across a membrane. -
ANSWER-Nonpolar can move across membrane, polar can't without carrier
protein
