Bio 131 chapter 4

A polypeptide is made of 31 amino acids. What is the minimum number of DNA nucleotides needed to code for this number of amino acids?

93 base pairs

Which of the following statements about codons are true?

A codon is a three-base sequence of mRNA.

Which of these demonstrate accurate base pairing according to the law of complementary base pairing?

A-T

An intron is a portion of mRNA that does not code for protein.

An intron is a portion of mRNA that must be removed before translation.

At one end of each tRNA there is a sequence of three nucleotides known as the _____. This sequence is complementary to the bases on mRNA.

Anticodon

Which of the following refers to a 3-base sequence found in tRNA?

Anticodon

In the nucleus, DNA is complexed with proteins to form a fine filamentous material called?

Chromatin

In the nucleus of a dividing cell, the chromatin condenses so that each _____, now made of two sister chromatids, can be seen with a light microscope

Chromosome

In the nucleus of a typical human cell, there are 46 DNA filaments. Which term refers to one of these structures?

Chromosome

A three-base sequence of mRNA is called a(n)

Codon

Where is RNA usually found?

Cytoplasm

Which statement best summarizes the role of DNA in protein synthesis?

DNA contains the genetic code that determines the amino acid sequences of proteins.

Which of the following statements are true regarding the DNA structure?

Each sidepiece is a sugar-phosphate backbone composed of phosphate groups alternating with the sugar deoxyribose.

Which molecules are responsible for modifying new proteins in the cistern of ER?

Enzymes

Following transcription, only some portions of the mRNA code for the final protein. The sections of mRNA that contain necessary code are called _____ , whereas the mRNA sections that do not code for the final protein are called _____.

Exons, introns.

If a protein is going to be used in the cytosol, it is likely to be made by ______. However, if it is going to be secreted from the cell, it is made by ______.

Free ribosomes, polyribosomes on the RER

A(n) _____ is an information-containing segment of DNA that codes for the production of a molecule of RNA, and that in most cases codes for one or more proteins.

Gene

A process by which the expression of a gene can be turned on (or off) according to the functions of cells or physiological needs. For example, casein is only produced when a mother is lactating. Name this process.

Gene regulation

When a woman gives birth the hormone prolactin stimulates her mammary glands to produce casein, a protein that her body has never synthesized before. This demonstrates which of the following?

Genes can be turned on or off.

Since there are no genes coding for carbohydrates, nucleic acids, or lipids, how do cells produce them?

Genes encode enzymes that synthesize these products.

Match the base triplet of DNA to the amino acid specified by the genetic code. CCA

Glycine

When synthesized proteins are to be exported out of the cells, they are packaged into secretory vesicles that originate in what organelle?

Golgi complex

When synthesized proteins at to be exported out of the cells, they are packaged into secretory vesicles that originate in what organelle?

Golgi complex

Which two nitrogenous bases are classified as purines?

Guanine, Adenine

Which enzyme is responsible for unwinding DNA during DNA replication?

Helicase

Match the base triplet of DNA to the amino acid specified by the genetic code. GTA

Histidine

Which of these proteins remain in the cell after being synthesized?

Histones, actin of cytoskeleton

Alternative splicing helps explain which of the following?

How one gene can produce more than one protein

Where does the making of mRNA from DNA take place?

In the nucleus

Translation occurs in three steps. Place these steps in chronological order.

Initiation, Elongation, Termination.

The first tRNA to bind to a ribosome at the start of translation is known as what?

Initiator tRNA

What is the role of mRNA in protein synthesis?

It carries the genetic code from the nucleus to the cytoplasm.

Match the subdiscipline of genetics with its description: Mendelian genetics

It deals with parent- offpspring and larger family relationships to discern and predict patterns of inheritance withing the family line.

How does newly synthesized mRNA pass from within the membrane-bound nucleus into the cytosol?

It passes through nuclear pores.

Which of the following are characteristics of ribonucleic acid (RNA)?

It plays an important role in the production of proteins. It contains nitrogenous bases A, U, C, G. It leaves the nucleus and can be found in the cytoplasm.

Match the subdiscipline of genetics with its description. Genomic medicine.

It studies the entire DNA endowment of an individual and how it influences health and disease.

Match the subdiscipline of genetics with its description. Molecular genetics.

It uses the techniques of biochemistry to study DNA structure and function.

Match the subdiscipline of genetics with its description. Cytogenetics.

It uses the techniques of cytology and microscope to study chromosomes and their relationship to hereditary traits.

During DNA replication, the new short segments of DNA in one of the strands are joined together by the enzyme DNA _____?

Ligase

In which of the following subdisciplines of genetics are family relationships analyzed to predict patterns of inheritance within a family line?

Mendelian genetics

Which of the following are components of nucleotides?

Nitrogenous bases, Phosphate groups, Sugars (ribose or deoxyribose)

The basic unit of a nucleic acid is shown in this picture. It is called a _____ and it has three components: a phosphate group, a sugar (like deoxyribose), and a nitrogenous base (like adenine).

Nucleotide

What are the monomeric subunits that comprise a molecule of DNA called?

Nucleotides

The nuclear envelope is perforated with openings called nuclear _____ that regulate the movement of molecules through the envelope.

Pores

Changes to the structure of a new protein (i.e removal of some amino acids, folding of the protein, adding carbohydrates, etc.) are collectively known as what?

Posttranslational modification

match each nitrogenous base with its description. Guanine

Purine that binds with cytosine

match each nitrogenous base with its description. Adenine

Purine that binds with thymine

match each nitrogenous base with its description. Thymine

Pyrimidine that binds with adenine

Match each nitrogenous base with its description. Cytosine.

Pyrimidine that binds with guanine

Which enzyme is responsible for transcribing DNA?

RNA polymerase

The process by which a cell makes a copy of its DNA so it can give complete and identical copies of all of its genes to each daughter cell is

Replication

The law of complementary base pairing state's that a cell can do which of the following?

Reproduce one strand of DNA based on information in the other.

After proteins are synthesized, some remain in the cell and some are secreted. Match each protein with its destination and function. Histones, RNA polymerase

Returned to the nucleus for cellular metabolism

______ are the cell structures that process coded genetic messages and assemble amino acids into proteins.

Ribosomes

When a protein must be exported outside the cell, it is synthesized in ribosomes bound to the ______ . Then it is modified and packaged into a ______

Rough endoplasmic reticulum, transport vesicle

After proteins are synthesized, some remain in the cell and some are secreted. Match each protein with its destination and function. Digestive enzymes

Secreted by exocytosis

Golgi vesicles containing proteins to be released from the cell will become which type of vesicle?

Secretory

True or false: It is possible to predict the sequence of one strand of DNA if we know the sequence of the complementary strand.

TRUE

Which of the following statements are true regarding the DNA structure?

The basic three-dimensional structure of DNA is the double helix.

Recall that the start codon is AUG. Based on this, the initiator tRNA will always have which anticodon?

UAC

After proteins are synthesized, some remain in the cell and some are secreted. Match each protein with its destination and function. Kinases, ATPases

Used in the cytosol as metabolic enzymes

Which of the following is a true statement?

Which proteins a cell makes is determined by which genes are activated in that cell.

Which molecule carries the genetic code from the nucleus to the cytoplasm?

mRNA

The ______ bases in DNA are adenine, cytosine, guanine and thymine.

nitrogenous

There are no genes that directly code for ______.

steroids, glycogen, phospholipids

Match the base triplet of DNA to the amino acid specified by the genetic code. CGT

Alanine

During translation, transfer RNA (tRNA) binds which molecule in the cytosol and delivers it to the ribosome?

Amino acid

An intron is a portion of mRNA that does not code for protein.

An intron is a portion of mRNA that does not code for protein.

Put the events of DNA replication in order starting with what happens first.

DNA helicase unwinds the double helix, DNA polymerase forms 2 new strands, one continuous and some as segments, DNA ligase closes the gap between newly formed segments, two DNA double helices result, each with a new and a parental strand.

Which molecules participate in DNA replication?

DNA, DNA ligase, DNA helicase, DNA polymerase

After proteins are synthesized, some remain in the cell and some are secreted. Match each protein with its destination and function. Sodium-potasium pumps

Delivered to the plasma membrane

Which of the following statements about codons are true?

The genetic code is expressed as a sequence of codons.

Which of the following statements are true regarding the DNA structure?

The nitrogenous bases face the inside and hold the two backbones together with hydrogen bonds.

What determines the amino acid sequence of a protein?

The nucleotide sequence in DNA

Place the steps of translation in the correct order, starting with what happens first.

The ribosome binds mRNA, A tRNA anticodon binds to a complementary mRNA codon, A new amino acod is linked to the growing peptide chain, The tRNA is released from the ribosome and is now available to pick up another.

Match the base triplet of DNA to the amino acid specified by the genetic code. TGC

Threonine

Which of the following can be considered the essential function of RNA?

To use the instructions coded in DNA to synthesize proteins

The enzyme RNA polymerase participates in which of the following processes?

Transcription

Which term refers to the step of protein synthesis in which DNA is used to make mRNA?

Transcription

The process of reading an mRNA molecule and synthesizing the protein encoded in its nucleotide sequence is known as

Translation

Which term refers to the conversion of nucleotide sequences into amino acid sequences?

Translation

_____ occurs in three steps called initiation, elongation, and termination.

Translation

A base _____ is a consecutive sequence of three DNA nucleotides that codes for one amino acid.

Triplet