Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/67

Click to flip

67 Cards in this Set

  • Front
  • Back
DNA directs cells activiites by telling it what _______ to make and when.
proteins
These proteins form ________ elements in the cell and regulate the production of _____ ______ products.
structural
other cell
By controlling protein synthesis, DNA is hugely important in directing _____.
life
Protein synthesis is a ____-step process.
two
Proteins are made in the ______?
cytoplasm
The cell copies the information held in DNA onto RNA molecules ina process called ________?
transcription
Proteins are synthesized at the ribosomes from the codes in RNA in a process called?
translation
Cells needt o be able to produce ____(#) different amino acids in order to produce all the proteins necessary to function.
20
How many nitrogen bases does DNA have?
4
In order to code for 20 amino acids, it is necessary to use _____(#) bases, which means a total of ______(#) coding combinations.
three
sixty four
These triplets of nucelotides that make up a single coding group are called _____ or _____?
codons or genes
CAG codes for the amino acid?
glutamine
CGA codes for the amino acid?
arginine
Codons are always read in an overlapping sequence. T or F
FALSE! It is non overlapping
If there are 64 codons, but oly 20 amino acids, what happens to the other 44 coding possibilites?
some of the codons call for the same amino acid
The genetic code is ______ because of its redundancy.
degenerate
There are also three ____ codons, which signals when a protein is fully formed.
stop
There is also one ____ codon, to signal the beginning of an amino acid sequence.
start
Since the sequence of nucelotides in DNA determines the order of amino acids in proteins, a ___ or ______ in the DNA sequence can affect a proteins funtion.
change
error
The errors or changes in a DNA sequence
mutations
What are the two basic types of mutations?
substitution mutations and frameshift mutations
A single nucelotide is replaced by a different nucleotide is a ____ mutation.
substitution
Mutations that have no effect at all are called ___ mutations.
silent
GAA coding for GAG will change to a different amino acid. T or F?
FALSE, it is still glutamate
Sickle cell anemia cripples human _____ _______ cells.
red blood
If the amino acid ______ is in a hemogoblin rather than glutamic acid, it will cause sickle-cell anemia.
valine
valine is GUA or ____, while the codon for glutamic acid is GAA or GAG. Changing to A or U makies the disease.
GUG
When a nucelotide is wrongly inserted or deleted from a codon, it results in a ________ mutation.
frameshift
Frameshift mutations are harmless. T or F?
FALSE! They are dehabilitating or lethal
An insertion or deletion will effect ____ codon in a gene sequence by throwing the entrie 3x3 codon structure out of whack.
every
When might a frameshift mutation not be be devastating? Why?
When an entire codon is deleted, because it will only result in one amino acid not being produced.
With the aid of special proteins called ________, the meters of DNA in a cell are coiled into an entangled fibrous mass.
histones
This fibrous mass of DNA is called ___________?
chromatin
When the cell replicates, the masses of chromatin gather together to create dicrete compact structures called ___________?
chromosomes
In eukaryotes, where are chromosomes located?
the nucleus
Where is the DNA located in a prokaryote cell?
a single chromosome that is joined in a ring in the cytoplasm
How many chromosomes do humans have?
46
How many pairs of these 46 chromosomes are there?
23
How many chromosomes do dogs have and in how many pairs?
78 in 39
Is a larger number of chromosomes a sign of biological sophistication?
no
The total number of distinct chromosomes in a cell is that cell's _______ number.
diploid
What are the cells in the human body that are not passed down to offspring called?
somatic cells
What do somatic cells contain?
chromosomes in 2 closely related sets, one set of 23 from a persons mother and father, a total of 46
The pairs of 23 that group together are known as ________ chromosomes
homologous
The ____ number of a cell refers to half of the total number of chromosomes in a cell (half the diploid number), or the number of homologoud pairs in somatic cells.
haploid
In humans and other higher animals, only the sex cells that are passed on to offspring have the haploid number of chromosomes. These sex cells are also called _____.
gametes
_____ helps DNA turn stored genetic messages into proteins.
RNA
What are the three crucial differences between DNA and RNA?
1)DNA's five-carbon sugar us deoxyribose, RNA nucelotidea contain a slightly different sugar called ribose.
2)RNA uses the nitrogenous base uracil instead of DNA's thymine
3)The RNA molecule takes the form of a single helix-half a spiral ladder-as compared with the double helix structure of DNA
during transcription, DNA is copied to make _______ _____ _______, which then leaves the nucleus to bring its still encoded information to the ribosomes in the cytoplasm.
messenger RNA (mRNA)
_____ ______ ______ moves amino acids to the site of protein synthesis at the ribosome according to the code specified by the mRNA strand
Transfer RNA (tRNA)
T or F, there are many different tRNAs, each of which bond to a different amino acid and the mRNA sequence corresponding to that amino acid.
true
DNA --transcription--> RNA --translation--> __________
protein
What is the first step in transcription?
partial unwinding of the DNA molecule so that the protion of DNA that codes for the needed protein can be transcribed
The enzyme called RNA polymerase helps line up nucelotides to create a ________ ________ of mRNA
complementary strand
Since mRNA is a single stranded molecule, ___ of the two strands of DNA is/are used as a template for the new RNA strand
one
The new strand of RNA is made according to the rules of base pairing: which are?
DNA cytosine pairs w/RNA (CG)guannine
DNA guanine pairs with RNA cytosine (GC)
DNA thymine pairs with RNA adenine (TA)
DNA adenine pairs with RNA uracil (AU)
The mRNA complement to the DNA sequence TTGCAC is?
AACGUG
After transcription, the new RNA strand is released and the two unzipped DNA strands bind together again to form the ________ _______.
double helix
The DNA template changes after transcription. T or F?
FALSE, it remains the same
Is it possible to tanscribe another identicle colecule of RNA immediately after the first one is complete?
yes
In translation, mRNA is sent to the _______ where is bonds with ribosomes, the sites of ______ synthesis.
cytoplasm
protein
How many important binding sites do the ribosomes have?
three
What are the ribosomes three important binding sites for?
one for mRNA and two or tRNA
What are the two tRNA sites labeled?
A site and P site
Once the mRNA is in place, tRNA molecules, each associated with specific ___ _____, bind to the ribosome in a sequence defined by the _______ code.
amino acids
mRNA
tRNA is made up of many nucelotides that bend into the shape of a ________?
cloverleaf
At its tail end, tRNA has an acceptor stem that attached to a specific ___ ____.
amino acid