Modules 6-8: Proteins, Enzymes, Nucleic Acids, and Cells

Flashcards created from lecture notes covering Module 6 (Proteins and Enzymes), Module 7 (Nucleic Acids), and Module 8 (Cells).

What is protein specificity?

A protein's ability to pick one specific target molecule.

What defines the primary structure of a protein?

The order of amino acids linked by peptide bonds.

What is denaturation in reference to proteins?

The disruption of a protein's 3-D structure.

What is a disulfide bond?

A covalent bond formed between cysteine side chains.

Which structural features make up the secondary structure of a protein?

Alpha helix and beta pleated sheets.

How is a peptide bond formed between amino acids?

Through the joining of two amino acids via a dehydration reaction.

What defines the quaternary structure of a protein?

Multiple protein subunits working together.

What is the tertiary structure of a protein?

The overall 3-D structure of a single protein polypeptide.

What four groups or atoms are attached to the central carbon of a basic amino acid?

A hydrogen atom ($\text{H}$), an amino group ($\text{H}_2\text{N}$), a carboxyl group ($\text{COOH}$), and an $\text{R}$ group (side chain).

Where is a peptide bond cleaved during a hydrolysis reaction?

It is cleaved at the bond between the carboxyl carbon ($\text{C=O}$) and the amino nitrogen ($\text{N-H}$) when water ($\text{H}_2\text{O}$) is added.

What causes the differences between different amino acids?

The $\text{R}$ group (side chain), which gives each amino acid its unique chemical properties.

What does the phrase 'shape determines function' mean when describing proteins?

A protein's specific shape allows it to interact with target molecules and perform its function; if its shape changes, it can no longer function properly.

What happens to a protein when the temperature gets too high?

High temperatures cause the protein to denature, changing its 3D shape and causing it to lose its function.

What happens to a protein when the pH level is too high or too low?

Extreme pH levels cause the protein to denature, resulting in a loss of its 3D shape and function.

Which pentose sugar is found specifically in DNA?

Deoxyribose sugar.

Which pentose sugar is found specifically in RNA?

Ribose sugar.

Which nitrogenous base is present in DNA but absent in RNA?

Thymine.

Which nitrogenous base is present in RNA but absent in DNA?

Uracil.

What group is present on the 2' carbon of the ribose sugar in RNA?

A hydroxyl group.

Is DNA single-stranded or double-stranded?

Double-stranded.

Is RNA single-stranded or double-stranded?

Single-stranded.

What is the primary function of DNA?

Passes genetic code to offspring.

What is the primary function of RNA according to the notes?

Copies genetic code to make proteins.

Where is DNA found in eukaryotic cells?

In the nucleus of eukaryotic cells.

What 3D shape describes the structure of DNA?

Double helix.

What category of sugar do both DNA and RNA contain?

Pentose sugar.

What monomer building blocks make up both DNA and RNA?

Nucleotides.

Which three nitrogenous bases are shared by both DNA and RNA?

Adenine, Guanine, and Cytosine.

What nitrogenous base pairs are found in DNA?

Adenine-Thymine ($\text{A-T}$) and Cytosine-Guanine ($\text{C-G}$).

What nitrogenous base pairs are found in RNA?

Adenine-Uracil ($\text{A-U}$) and Cytosine-Guanine ($\text{C-G}$).

Which bases are complementary to each other in DNA?

Adenine is complementary to Thymine ($\text{A-T}$), and Cytosine is complementary to Guanine ($\text{C-G}$).

Which bases are complementary to each other in RNA?

Adenine is complementary to Uracil ($\text{A-U}$), and Cytosine is complementary to Guanine ($\text{C-G}$).

What does the term 'complementary strands' mean?

The base sequence of one strand determines the sequence of the other strand because each base only pairs with its specific complementary base.

How does the term 'antiparallel' apply to DNA?

The two strands of DNA run side by side but in opposite directions.

How does the term 'double helix' apply to DNA?

It describes the twisted, ladder-like spiral structure formed by two complementary DNA strands.

What are the three essential components of a nucleic acid nucleotide?

A phosphate group, a pentose sugar (deoxyribose or ribose), and a nitrogenous base.

How does the location of DNA differ between eukaryotic and prokaryotic cells?

In eukaryotic cells, DNA is located in the nucleus; in prokaryotic cells, DNA is found in the nucleoid.

Can eukaryotic organisms be unicellular, multicellular, or both?

Eukaryotic organisms may be unicellular or multicellular.

Are prokaryotic organisms unicellular or multicellular?

Prokaryotic organisms are always unicellular.

Which cell type contains membrane-bound organelles?

Eukaryotic cells.

What small circular DNA molecule is found in prokaryotic cells?

Plasmid.

What key cellular features are shared by both eukaryotic and prokaryotic cells?

DNA as genetic material, cytoplasm, ribosomes, and a phospholipid bilayer membrane.

What is the overall purpose of the cytoskeleton?

It provides structure and support, helps maintain cell shape, organizes and moves organelles, and helps with cell movement and division.

List the protein fibers of the cytoskeleton from largest to smallest.

Microtubules $\rightarrow$ Intermediate filaments $\rightarrow$ Microfilaments.

True or False: Cells are the smallest unit of life.

True.

True or False: Microtubules are the smallest filaments of the cell.

False (Microtubules are the largest protein fibers of the cytoskeleton; microfilaments are the smallest).

True or False according to the Module 8 Venn diagram: Prokaryotic and Eukaryotic cells both have a cytoskeleton.

False (The Module 8 Venn diagram categorizes containing a cytoskeleton specifically under Eukaryotic cells).

True or False: Only Eukaryotic cells carry DNA as genetic information.

False (Both eukaryotic and prokaryotic cells use DNA as their genetic material).

What is the definition of an organelle according to the cell review section?

An organelle is a tiny structure inside a cell.

True or False: Eukaryotic and Prokaryotic cells both have membrane-bound organelles.

False (Only eukaryotic cells possess membrane-bound organelles).