Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
85 Cards in this Set
- Front
- Back
|
Function of chromosomes |
Carry genetic material inside the cell |
|
|
What are genes composed of |
Simply sections of chromatin |
|
|
What do chromosomes contain? |
Several hundred genes in a linear fashion |
|
|
What is chromatin composed of? |
Protein and uncoiled DNA |
|
|
What is DNA composed of? |
Specific sequences of nucleotides(monomers) |
|
|
What is the structure of the double helix? |
-Rungs of ladder are nucleotide bases -side rails are sugars and phosphates |
|
|
What is each nucleotide in DNA composed of? |
-5 carbon sugar(deoxyribose) -A phosphate group -A nitrogen-containing compound(base) |
|
|
Characteristics of deoxyribose |
-The sugar in a DNA molecule -forms the side rails of ladder -contains one less oxygen than the sugar of ribose. - A 5 carbon ring called pentose. |
|
|
Characteristics of bases |
-Rungs of the ladder -Formed by pairs of 4 of the 5 nitrogenous bases -The bases project at right angles off the sugar phosphate backbone. |
|
|
4 bases including for RNA |
-(A) Adenine -(G)Guanine -(T) Thymine or (U) Uracli in RNA -(C)Cytosine |
|
|
2 classes of bases |
Pyrimidines-The smaller nucleotides, single nitrogen ring. Thymine, Cytosine and Uracil -Purines- The larger nucleotides, double nitrogen ring, Adenine and Guanine. |
|
|
What type of bond holds together the two bases that form the rung of the ladder? |
weak Hydrogen bonds |
|
|
Bases are always a pyrimidine pairing with a... |
Purine |
|
|
Pyrimidine T always pairs with.. |
Purine A |
|
|
Pyrimidine C always pairs with.. |
Purine G |
|
|
What does DNA coil around to make a chromosome? (Eukaryotes only) |
A strand of histone proteins |
|
|
RNA properties |
-A copy of one small sequence of DNA -Makes its way to a ribosome -Used to form proteins |
|
|
RNA structure |
-Contains Ribose instead of deoxyribose. -Has one more oxygen than deoxyribose -Single stranded |
|
|
In RNA Uracil bonds with... |
Adenine |
|
|
3 types of RNA found in a cell |
-Messenger RNA - Ribosomal RNA - Transfer RNA |
|
|
DNA Replication |
-Before the cell divides each chromosome makes an exact copy of itself |
|
|
Eukaryotic cells divide by what? |
Mitosis (one cell splits into two) |
|
|
Prokaryotic cells divide by what? |
Binary Fission (A cell wall forms and the inner membrane pulls the chromosomes to the two new daughter cells) |
|
|
What breaks the hydrogen bonds for cell replication? |
Replication enzymes (helicase) |
|
|
Where do the pulled apart DNA strands get new nucleotides? |
The Nucleoplasm which is loaded with molecules including A,G,T and C. |
|
|
What attaches free floating nucleotides to exposed bases? |
The enzyme DNA Polymerase |
|
|
Semi-conservative replication |
Means we conserve the old DNA and build new complementary bases to build each new double helix. |
|
|
What determines the sequence of amino acids in a protein and therefore its identity? |
DNA |
|
|
How do Chromsomes synthesize proteins? |
The DNA of chromosomes makes RNA which makes proteins.. this is called the Central Dogma |
|
|
3 types of RNA |
Messenger RNA Ribosomal RNA Transfer RNA |
|
|
Messenger RNA Function |
Carries information from the DNA to the cytoplasm where the protein will be manufactured. |
|
|
Ribosomal RNA function |
Ribosomal RNA and the nucleolus make ribosomes. A ribosome is two proteins put together. |
|
|
Transfer RNA function |
Transfers amino acids from the cytoplasm to the ribosomes and positions it properly in the growing protein chain. |
|
|
Transfer RNA is specific for two things |
-the amino acid it carries -the section of the mRNA it binds to, called the codon |
|
|
Transcription |
A sequence of bases in DNA is used to form an RNA molecule with a matching sequence of bases. |
|
|
Does the entire DNA unwind for transcription? |
No, only the part needed to make the specific protein |
|
|
What are the long segments in DNA that do not code for anything called? |
Introns |
|
|
What are the coding sections in DNA called? |
Exons |
|
|
Before RNA leaves the Nucleus what happens to the introns and exons? |
The introns are cut out and the exons are spliced together. |
|
|
What is Mature RNA? |
It's the RNA that then moves to the cytoplasm after the introns have been cut out and the exons have been spliced together |
|
|
Translation |
Process in which the language of RNA is translated into the language of proteins |
|
|
Translation:mRNA joins with a ribosome |
-Temporarily joins together -Amino acids are brought to the union by tRNA -The ribosome has a spot for the mRNA to move into where it is read and we know what amino acid to bring in what order |
|
|
Translation:tRNA |
-One tRNA molecule for each of the amino acid types -Each tRNA only attaches one type of amino acid
|
|
|
What is a Codon? |
-A nucleotide triplet on mRNA -codes for the insertion of one amino acid in a protein |
|
|
What is Anticodon? |
A region of a tRNA molecule consisting of 3 sequential nucleotides that will have a matching codon in mRNA. |
|
|
Protein chain synthesis process |
-Ribosome attaches to one end of mRNA -Ribosome waits at each mRNA triplet(Codon) for tRNA to drift into position -peptide bonds form between amino acids -tRNA moves away leaving amino acid behind -Ribosome moves along |
|
|
Translation importance |
determines correct sequence, correct shape and correct function of the cell. |
|
|
DNA's 4 nucleotide bases code for how many amino acids? |
20 |
|
|
Stop codons are.. |
UGA, UAA, UAG |
|
|
Two major parts of cell cycle |
-Interphase (90% of the time) -Cell division |
|
|
Interphase |
-A state of non-division -cells are carrying out their normal activities |
|
|
3 parts of interphase |
1. G1(growth 1) 2. Synthesis 3. G2 (growth 2) 4. ? G0 |
|
|
G1 |
G1 (growth1)- cell increases in size by forming new substance like proteins.-getting ready for cell division-Large amount of protein synthesis in this stage. |
|
|
Synthesis |
-DNA and chromatin duplicates -When the cell has decided to reproduce and split -chromosome number of the cell now doubles -only takes a few hours to complete |
|
|
G2 (growth 2) |
-The cell synthesizes specific proteins for mitosis. - xtra organelles are formed for the eventual new cell. - a new centriole is made -last a couple hours |
|
|
G0 |
-Like an extended G1 -The newly formed cell grows and matures but cannot divide and so will never enter the S Phase. |
|
|
Chromatin |
Uncoiled DNA in a nucleus (2 sets of 23) |
|
|
Chromosomes |
What chromatin coils and condenses to become |
|
|
How many chromosomes in a cell? |
46 (92 after S phase) |
|
|
Centromere |
Narrowed portion of chromosome that has been replicated holds the two copies together until ready for seperation |
|
|
Chromatid |
A name for the chromosome copy attached to the centromere to avoid confusion
|
|
|
Homologues |
Similar chromosomes that carry the same genes but not the same traits. Ie. hair color and eye color genes but different colors |
|
|
What happens after interphase? |
Mitosis |
|
|
Mitosis |
-Technically division of the Nucleus but used to also include cytokinesis. A single parent cell divides to produce 2identical daughter cells having the same number and kind of chromosomes as theoriginal parent. |
|
|
Cytokinesis |
Cytoplasm division and division of all its contents into two new daughter cells. |
|
|
4 stages of mitosis |
1. Prophase 2. Metaphase 3. Anaphase 4. Telophase |
|
|
Prophase (Chromatin become chromosomes) |
-Follows G2 of interphase -Chromatin shorten up and coil into individual chromosomes -The nuclear membrane disappears -92 chromosomes |
|
|
What is formed during Prophase? (P for pros go first) |
Spindle fibers of the mitotic spindle begin to form |
|
|
What is the function of the mitotic spindle? |
To eventually pull apart the chromatids |
|
|
Metaphase (M for middle phase) |
-2nd phase of mitosis -Chromsomes line up on equatorial plane -Chromosomes attach to spindle fibers |
|
|
Anaphase |
-Centromereslit and chromatids are pulled to either side. -cleavage furrow begins (pinching of the cell membrane) |
|
|
Do plants form a cleavage furrow? |
No, they begin to form a new cell wall between the divided chromosome
|
|
|
Telophase |
Cleavage is completed and 2 sister cells are formed -Cell enters either G0 or G1(G1 can split again) |
|
|
What is Meiosis unique to? |
Reproductive cells (gametes) |
|
|
Meiosis definition |
How a cell with 2 complete sets of chromososmes halves their number so they only have 1 set of 23. |
|
|
How many chromosome pairs in Humans? |
23 |
|
|
Diploid cell (D as in double) |
Cells with both members of each homologous pair of chromosomes |
|
|
Haploid cells |
Cells with one member of each homologous pair of chromosomes -Ex. sperm cells and eggs |
|
|
In meiosis a diploid becomes a ... |
Haploid |
|
|
Where does meiosis take place? |
Gonads...ovaries and testes |
|
|
Meiosis takes place in how many steps? |
2 steps |
|
|
2 steps of Meiosis |
Meiosis I and meiosis II |
|
|
Summary of Meiosis |
-Meiosis halves the chromosome number to form sperm and eggs -Meioisis provides a means of shuffling genes |
|
|
Mitosis facts |
1. Cells undergo one division 2. No genetic exchange between chromosomes 3. Produces 2 identical cells 4. Chromosome # constant with even distribution to daughter cells 5. Occurs in most cells 6. Daughter cells are genetically similar 7. Daughter cells can undergo mitosis |
|
|
Meiosis facts |
1. Cell undergoes two divisions 2. Chromosomes exchange parts (crossover) 3. Produces 4 cells 4. Halves Chromosome # before distributing to daughter cell 5. Only in formation of eggs and sperm 6. Daughter cells genetically different 7. Daughter cells cannot undergo meiosis again |
