Biology: Second Unit Test

What are Proteins made of?

Long chains of amino acids

What is the basic structure of amino acids?

Carboxyl group and amino functional groups

What makes an amino acid unique?

The presence of a variable, or R group

What are R groups?

R Groups give each amino acid its chemical properties

What are are amino acids linked together by?

Peptide Bonds, forming long polypeptide chains

As polypeptide chains form...

the polypeptide develops multiple levels of structure, which gives the protein its shape

The different levels of a polypeptide are?

Primary, Secondary, Tertiary, and Quaternary

What is the Primary Structure of a Polypeptide?

The order of amino acids in the polypeptide chain

How many different amino acids are there?

20

What is the Secondary Structure of a Polypeptide?

A pleated sheet or helix like structure that a protein chain can form due to hydrogen bond or other chemical attractions between the R groups of other amino acids

What is the Tertiary Structure of a Polypeptide?

The overall shape of a polypeptide. It is created when the secondary structure folds and twists over itself. Held in place by multiple bonds.

At what point is a protein considered a protein?

When the Polypeptide forms the Tertiary Structure they are considered Proteins

When is a Quaternary Structure formed?

When proteins interact with other proteins to form large protein complexes

How are Proteins made?

Protein Synthesis

What determines how proteins are made?

Genes

What are Chaperonins?

A type of proteins that helps in the folding of polypeptide chains (barrel shape)

What are some functions of proteins?

Transporting, signaling, receiving, catalyzing for storing, defending, or movement

What are Enzymes?

A protein that speeds up chemical reactions

What are antibodies?

A protein that binds to foreign objects and destroys them

What is the backbone of the polypeptide made of?

The Carboxyl group and the Amino functional groups

What is Adenosine Triphosphate/ATP?

Energy that is used in getting a substance in or out of the membrane

What is the structure of ATP?

three phosphates, a 5-carbon sugar, and nitrogenous base (Adenine)
three circles, pentagon, rectangle

What is ATP classified as?

A special nucleotide (can not go into DNA or RNA)

What happens when the bond between the third and second phosphate is broken in ATP?

A lot of energy is created

What is a Lysosome?

A membrane bound organelle that contains enzymes to break down substances

What do Antibodies do?

They get rid of foreign substances and aid your immune system in making sure you don't get sick. (y-shaped proteins)

How do Antibodies work?

They bind to foreign substances and destroy them

Where do Antibodies start?

In the B Cells and then go to the rest of the body

What do Enzymes (outside of digestion) do?

Speed up chemical reactions (Bind of specific substances and break them down)

What are some examples of Antibodies and what do the examples do?

IgA (protects against inhaled and ingested pathogens), IgG (protects from viral and bacterial infections)

What are some examples of Enzymes and what do they do? examples do?

Polymerase (synthesize long chains of nucleic acids), Hydrolase (breaks down bonds with water), Helicase (breaks down double-stranded DNA into single-stranded DNA)

What do Structural Proteins involved in movement do?

They aid in the movement of your muscles

How do Structural Proteins move muscles?

Actin and Myosin allow your muscles to contract

What do Hormone/Messenger Proteins do?

They transmit signals to coordinate biological processes between different cells, tissues, and organs

How do Hormone/Messengers Proteins work?

The protein receptor on the membrane binds to the hormone and reads the hormones message and carries out the instructions

What are some examples of Hormone/Messengers Proteins and what do the examples do?

Insulin (makes it possible to adsorb sugar)
Adrenaline (induces "fight or flight" instincts)
Growth Hormones (help in growth and development throughout childhood)

What do Structural Proteins do?

Help keep the structure of the cell

What makes a protein specialized?

The shape of the protein determines how that protein will work

What are some examples of Structural Proteins and what do the examples do?

Collagen (makes tissues strong and flexible)
Laminin (directs pathways and activities in cells)
Keratin (forms tissues for nails, hair, and skin)

What do the Enzymes involved in digestion do?

They break down the food you eat to turn nutrients into substances that can be used

What are some examples of Enzymes that are involved in digestion and what do they do?

Amylase (helps digest carbohydrates)
Maltase (catalyzes the hydrolytic process of Maltose which makes d-glucose)
Lactase (helps you digest lactose)
Trypsin

What are Storage Proteins?

A reservoir for nutrients that can be used later in a cell

How do Storage Proteins work?

Hold on to substance such as metal ions or amino acids for the development of an organism

What are some examples of Storage Proteins and how do they work?

Albumins (hold fluids for our blood vessels)
Prolamins (keeps your intestines not permeable)
Glutelins (hold onto substances that give you energy)

What directs the functions of the cell?

nucleic acids

What is the function of lipids?

To provide the body with insulation (fat) and long term energy storage

Why do Cardiac muscle cells have a higher concentration of mitochondria than skeletal muscle cells?

Cardiac muscle cells require a larger supply of energy released through respiration

What is the Central Dogma in Molecular Biology?

DNA ---> RNA ---> Proteins

What is a gene?

A specific segment of DNA that carries the instructions for a specific protein

What is Transcription?

Process in which the genetic code (genetic instructions) within DNA is transcribed or summarized into mRNA.

What main two process must take place during protein synthesis?

Transcription and Translation (some editing is done to the mRNA before translation occurs)

What does Protein Synthesis do?

Creates Proteins

Where does Transcription take place?

In the nucleus

What are the three steps of transcription?

Initiation, Elongation, Termination

What is Initiation?

When the enzyme RNA polymerase binds to the promoter region of the gene and signals the DNA to unwind so the enzyme can read the bases.

What is Elongation?

The RNA polymerase reads the unwound DNA and builds mRNA using base pairings (Adenine binds to Uracil during this step)

What is Termination?

Happens when RNA polymerase crosses a stop (termination) sequence in the gene, mRNA strand detaches form the DNA

What must happen before newly formed mRNA leaves the nucleus?

The mRNA must go through additional processing

What are the three different types of additional processing?

Splicing, Editing, and Polyadenylation

What is Splicing?

A form of additional processing done to newly made mRNA
Removes introns, leaving only exons behind

What are introns?

Regions within mRNA that do not code for proteins

What are exons?

Regions within mRNA that do code for proteins

What is Editing?

A form of additional processing done to newly made mRNA
Changes some of the nucleotides in mRNA

What is Polyadenylation?

A form of additional processing done to newly made mRNA
Adding of a "tail" to the mRNA, which consists of Adenine bases to signal the end of mRNA
Tails protect mRNA from enzymes that try to break it down

In what type of cell, does additional processing happen?

Eukaryotic Cells

What is Transcription in relation to the Central Dogma of Molecular Biology?

DNA --> RNA

After mRNA is created (and possible additional processing), how does the mRNA leave the nucleus?

Through a nuclear pore

In a strand of codons, which codon is almost always first and is considered a "start" codon?

AUG

What is a codon?

A group of three nitrogenous bases which is read during translation. Codons code for a specific amino acid

What is tRNA?

A molecule that brings amino acids to the ribosome in the correct sequence

What is at the bottom of tRNA?

Anticodons. Anticodons are 3 nitrogenous bases that bind to the complementing codon

What type of bond forms between two amino acids brought down by tRNA?

Peptide bond

What is Translation?

Process in which the genetic code in mRNA is read one codon at a time to make a protein

What is Translation in relation to the Central Dogma?

RNA --> Protein

Where does the newly formed mRNA move to once it is in the cytoplasm?

A ribosome

What happens once the mRNA moves into the ribosome?

The ribosomes read the sequence of codons in the mRNA. Then tRNA brings the amino acids that correspond to the codons

How many different amino acids does the bases A, T/U, C, G code for?

20

What is the definition of the genetic code?

Code that changes the information in DNA and RNA into ordered amino acids and proteins

What does each codon code for?

One amino acid or a stop or start codon

What does AUG code for?

Methionine/start codon

What three words describe the genetic code?

Universal, Unambiguous, and Redundant.
All organisms use the genetic code
Each codon codes for only one amino acid
Most amino acids are encoded by more than one codon

How many possible codons are their?

64

What is the rough endoplasmic reticulum (rER)?

An organelle with many ribosomes attached to it
Serves as the many place for proteins to be made and modified

What is the smooth endoplasmic reticulum (sER)?

An organelle in which lipids are created and modified

After proteins are created in the rER, they can go to...

The Golgi Apparatus where they can be modified and turned into vesicles for transport substances in and out of the cell (secretory pathway)

After a protein is created how is it modified?

The rER can modify the protein to do many different jobs such as: become a peroxisome, aid in the nucleus, aid in the rEr, stay in the cytoplasm, become a lysosomes, etc.

What is a mutation?

A change in nitrogenous bases of DNA and RNA

What is a Mutagen?

Something that causes a mutation

What is a Germline Mutation?

A mutation in the genetic code
Serious and can be passed to offspring

What is a Somatic Mutation?

A mutation that occurs in a somatic (non-gamete) cell
Not serious and only occurs in one cell or daughter cell
Cannot be passed onto offspring

What is Chromosomal Alteration?

A mutation that changes chromosome structure/genetic material
Occurs when part of a chromosome breaks off and doesn't rejoin correctly
Can occur because of deletion, duplication, inversion, insertion, or translocation

What is a Point Mutation?

A mutation that changes one nucleotide
Less serious
Several Types

What is a Frameshift Mutation?

A mutation in which a nucleotide is deleted or inserted causing everything to shift over, greatly impacting protein synthesis

What is a Genetic Disorder?

A disease caused by a gene mutation

What causes a mutation?

Most are accidental and random but some can be caused by mutagens.

What are some examples of a mutagen?

Chemicals (Cigarette smoke, Barbecuing)
Infectious Agents (HIV)
Radiation (UV radiation, X-Rays)

How many different types of point mutations are their and what are they?

3. Silent Mutation, Missense, and Nonsense

What is a Silent Mutation?

A type of point mutation, in which a mutated codon (a nitrogenous base gets changed) codes for the same amino acid

What is a Missense Mutation?

A type of point mutation, in which a mutated codon (a nitrogenous base gets changed) codes for a different amino acid

What is a Nonsense Mutation?

A type of point mutation, in which a mutated codon (a nitrogenous base gets changed) codes for a stop codon, ending the protein synthesis early