Chapter 21 Pt. 1 Flashcards
DNA is sometimes called the ______ __ _____
thread of life
What is DNA?
a double-stranded molecule resembling a ladder that is gently twisted to form a spiral called a double helix
DNA is a double-stranded molecule resembling a ladder that is gently twisted to form a spiral called a _______ _____
double helix
What does DNA stand for?
Deoxyribonucleic Acid
Each side of the ladder is made from a string of repeating subunits called ___________
nucleotides
What is a nucleotide?
composed of the subunits, including one sugar, one phosphate, and one nitrogenous base
A nucleotide is composed of the subunits, including one ______, one _________, and one __________ _____
sugar
phosphate
nitrogenous base
What are the four nitrogenous bases of DNA?
Adenine (A)
Thymine (T)
Guanine (G)
Cytosine (C)
The sides of the ladder (of DNA) are composed of __________ _______ and _________; the rungs consist of paired ___________ ______
alternating sugars
phosphate
nitrogenous bases
According to Complementary Base Pairing:
________ (__) only pairs with Thymine (T)
Cytosine (C) only pairs with ________ (__)
Adenine (A)
Guanine (G)
According to Complementary Base Pairing:
Adenine (A) only pairs with ________ (__)
________ (__) only pairs with Guanine (G)
Thymine (T)
Cytosine (C)
Complementary base pairings are held together by weak _________ ______
hydrogen bonds
True or False: Complementary base pairings are held together by strong hydrogen bonds
False; Complementary base pairings are held together by weak hydrogen bonds
The DNA within each human cell has how many base pairs?
3 billion base pairs
What is Nuclei Acid?
a molecule formed by the joining of nucleotides
DNA is a _______ ____
nucleic acid
True or False: DNA is copied after mitotic and meiotic cell division
False; DNA is copied before mitotic and meiotic cell division
DNA Replication:
- the nitrogenous bases on the separated regions of each strand are temporarily exposed
- free nucleotide bases, can then attach to complementary bases on the open DNA strands
- DNA Polymers
- As each of the new double-stranded DNA molecules forms, it twists into a double helix
- Semiconservative replication
- begins when an enzyme breaks the weak hydrogen bonds that hold together the paired bases that make up nucleotide strands of the double helix, thereby “unzipping” and unwinding the strands
DNA Replication:
- begins when an enzyme breaks the weak hydrogen bonds that hold together the paired bases that make up nucleotide strands of the double helix, thereby “unzipping” and unwinding the strands
- free nucleotide bases, can then attach to complementary bases on the open DNA strands
- DNA Polymers
- As each of the new double-stranded DNA molecules forms, it twists into a double helix
- Semiconservative replication
- the nitrogenous bases on the separated regions of each strand are temporarily exposed
DNA Replication:
- begins when an enzyme breaks the weak hydrogen bonds that hold together the paired bases that make up nucleotide strands of the double helix, thereby “unzipping” and unwinding the strands
- the nitrogenous bases on the separated regions of each strand are temporarily exposed
- DNA Polymers
- As each of the new double-stranded DNA molecules forms, it twists into a double helix
- Semiconservative replication
- free nucleotide bases, can then attach to complementary bases on the open DNA strands
DNA Replication:
- begins when an enzyme breaks the weak hydrogen bonds that hold together the paired bases that make up nucleotide strands of the double helix, thereby “unzipping” and unwinding the strands
- the nitrogenous bases on the separated regions of each strand are temporarily exposed
- free nucleotide bases, can then attach to complementary bases on the open DNA strands
- As each of the new double-stranded DNA molecules forms, it twists into a double helix
- Semiconservative replication
- DNA Polymers
DNA Replication:
- begins when an enzyme breaks the weak hydrogen bonds that hold together the paired bases that make up nucleotide strands of the double helix, thereby “unzipping” and unwinding the strands
- the nitrogenous bases on the separated regions of each strand are temporarily exposed
- free nucleotide bases, can then attach to complementary bases on the open DNA strands
- DNA Polymers
- Semiconservative replication
- As each of the new double-stranded DNA molecules forms, it twists into a double helix
DNA Replication:
- begins when an enzyme breaks the weak hydrogen bonds that hold together the paired bases that make up nucleotide strands of the double helix, thereby “unzipping” and unwinding the strands
- the nitrogenous bases on the separated regions of each strand are temporarily exposed
- free nucleotide bases, can then attach to complementary bases on the open DNA strands
- DNA Polymers
- As each of the new double-stranded DNA molecules forms, it twists into a double helix
6.
- Semiconservative replication
____ _______ are enzymes that link the sugars and phosphates of the newly attached nucleotides to form a new strand
DNA Polymers
DNA Polymers are enzymes that link the _______ and __________ of the newly attached nucleotides to form a new strand
sugars
phosphates
______________ ___________- in each of the new double-stranded DNA molecules, one original (parent) strand is saved (conserved) and the other (daughter) strand is new
Semiconservative replication
DNA directs the synthesis of __________ _____ (____)
ribonucleic acid (RNA)
_________ _____- directs the synthesis of a polypeptide ( a part of a protein) or a protein
ribonucleic acid
ribonucleic acid- directs the synthesis of a ___________ ( a part of a protein) or a _______
polypeptide
protein
What is a gene?
a segment of DNA that contains the instructions for producing a specific protein (or, in some cases, a specific polypeptide)
What is the process of gene expression?
DNA-> RNA-> Protein
RNA is the intermediary that comes the information encoded in _____ from the nucleus to the cytoplasm and directs the _________ of the specified protein
DNA
synthesis
RNA is the intermediary that comes the information encoded in DNA from the ________ to the __________ and directs the synthesis of the specified protein
nucleus
cytoplasm
RNA is composed of nucleotides linked together:
______(__) pairs with Adenine (A)
Uracil (U)
RNA is composed of nucleotides linked together:
Uracil (U) pairs with _______(__)
Adenine (A)
What transcription?
the first step in converting the DNA message to a protein by copying the message as RNA
Transcription:
____->____
DNA
RNA
How are DNA and RNA similar?
- are nucleic acids
- are composed of link nucleotides
- have a sugar-phosphate backbone
- have 4 types of bases
Is this DNA or RNA:
is a double-stranded molecule
DNA
Is this DNA or RNA:
has a sugar deoxyribose
DNA
Is this DNA or RNA:
contains the bases adenine, guanine, cytosine, and thymine
DNA
Is this DNA or RNA:
functions primarily in the nucleus
DNA
Is this DNA or RNA:
is a single-stranded molecule
RNA
Is this DNA or RNA:
has a sugar ribose
RNA
Is this DNA or RNA:
contains the bases adenine, guanine, cytosine, and uracil
RNA
Is this DNA or RNA:
functions primarily in the cytoplasm
RNA