Module 1a: Chemistry and functional groups
Monomers combine to form ________ through the process of ________.
Polymers; dehydation synthesis
Which biomolecule is responsible for insulation and LONG term energy storage?
Lipids
A region along one DNA strand has the following sequence of nitrogenous bases: 5'-TAGGCCT-3'. Write down its complementary strand, labeling the 5' and 3' ends.
3'-ATCCGGA-5'
Which structure is not part of the endomembrane system?
(A) nuclear envelope
(B) chloroplast
(C) Golgi apparatus
(D) plasma membrane
(B) chloroplasts
A steroid hormone has undergone a mutation that makes it polar instead of nonpolar. How might this interfere with its function?
A) The polar hormone won't be released by glands
B) The polar hormone won't be able to travel in the blood stream to reach its target
C) The polar hormone will get stuck in the inside of the cell membrane
D) The polar hormone won't be able to pass through the cell membrane to reach its target
D) The polar hormone won't be able to pass through the cell membrane to reach its target
Nonpolar molecules are hydrophobic similar to lipids. They can all therefore dissolve in the lipid bilayer of the membrane and cross it easily, without the aid of membrane proteins. Larger polar molecules and charged molecules cannot pass through.
Identify each solution as neutral, acidic, or basic.
a) pH = 7.20
b) pH = 15.3
c) pH = 4.60
a) 7.20 = neutral
b) 15.3 = basic
c) 4.60 = acidic
What's the difference between saturated and unsaturated fats?
Saturated fatty acids lack double bonds between the individual carbon atoms, while in unsaturated fatty acids there is at least one double bond in the fatty acid chain.
Why does a denatured protein no longer function normally and what can changes or factors can denature a protein?
Denaturation - unfolding or breaking up of a protein's 3D structure. Proteins may be denatured by pH changes, heat or enzyme activity can cause a protein to unfold or its polypeptide chains to become non-functional.
What role do ribosomes play in carrying out genetic instructions?
Ribosomes in the cytoplasm translate the genetic code from the DNA in the nucleus through transcribed mRNA, into a polypeptide chain.
DNA is transcribed –> mRNA –> translated by ribosome
What role do vescicles play in the endomembrane system?
The transport vesicles facilitate the movement of membranes and materials that they encapsulate among other endomembrane system elements.
How do oxygen and hydrogen share electrons? Which atom is more electronegative? Why?
Covalent bond because oxygen shared the electrons unequally with hydrogen.
Oxygen pulls bonded electrons towards itself and gets a slightly negative charge while both hydrogen atoms get a slightly positive charge.
Oxygen is more electronegative (more electrons around it).
What is the difference in function between starch and cellulose, when found in plants?
Starch = store energy for plants
Cellulose = provide strength and rigidity to the plant cell wall
What structural features allows DNA to replicate itself?
Double helix (two stranded shape) made up of complementary bases.
When the two strands are separated, each can be a template to form the new strand. A always pairs with T, and C with G, allowing correct strands to form.
Describe the structural and functional distinctions between rough and smooth ER.
The bound ribosomes on the rough ER are the main characteristic that separates it from the smooth ER. Both forms of ER create phospholipids but, the rough ER's ribosomes are responsible for producing secretory and membrane proteins. In addition, the smooth ER is involved in calcium ion storage, detoxification, and metabolism of carbohydrates.
Describe the geometry and properties of a water molecule (2). What bond does it have?
Polar, hydrophillic, covalent bonds.
Capable of hydrogen bonding.
Cohesion.
Which of the following is the best explanation for why soaps can dissolve oily substances?
A) The hydrocarbon tails of soap are nonpolar so they are soluble in oil
B) The hydrocarbon tails of soap are polar so they are soluble in oil
C) The charged groups of soap are polar so they are soluble in water
D) The charged groups of soap are nonpolar so they are soluble in oil
A) The hydrocarbon tails of soap are nonpolar so they are soluble in oil
The nonpolar portion of the soap molecule can dissolve other nonpolar substances like fats, oils, and other lipids. Remember the saying, “like attracts like.”
What parts of a polypeptide participate in the bonds that hold together secondary structure? What about tertiary structure?
The polypeptide backbone has hydrogen bonds to maintain the secondary structure.
Then for tertiary structures, R groups from amino acids hold it together.
What properties of carbon allows it to play a part in the structural and functional diversity of biological macromolecules associated with life?
Describe the atomic structure and resultant valence of carbon.
With four valence electrons, carbon can covalently bond to oxygen, hydrogen, and nitrogen to form the many molecules important for cellular function.
Form covalent bonds to as many as four different atoms. It's a versatile element ideal to serve as the basic structural component, or “backbone,” of the macromolecules.
A dehydration reaction joins two glucose molecules to form maltose. The formula for glucose is C6H12O6. What is the formula for maltose and can you draw the reaction?
C12H22O11