Unit 4 - Cell Replication Study Guide Flashcards
What are the steps of mitosis?
Prophase - Chromatin form chromosomes & centrioles form spindle fibers
Metaphase - Chromosomes line up in the middle (equatorial plate)
Anaphase - Chromosomes split apart and spindle fibers move them to the poles
Telophase - Chromosomes uncoil becoming chromatin, spindle fibers dissappear, & cell membrane is formed
ββ
πΉπππππ: Two identical daughter cells
Start Chromosomes: 46
End Chromosomes: 46
Define cytokinesis
Last step of the cell cycle where the cytoplasm divides into two cells
What are the phases of the Cell Cycle of somatic cells?
-
Interphase
G1 (Gap 1-growth) phase
S-(Synethsis) phase
G2 (Gap 2-growth) phase -
Mitosis
Prophase
Metaphase
Anaphase
Telophase - Cytokenisis
What is the function of stem cells?
Bodies repair system; regenerates cells in organs
Where are stem cells produced?
- Bone Marrow
- Blood
- Adipose tissue
(*Can also be artificially grown)
General characteristics of Viruses
- Non-living particle
- Cytoplasm covered by protein coat called capsid; NO cell parts
- 3 groups:
- Bacterial viruses
- Plant viruses
- Animal viruses
HIV (Human immunodeficiency Virus)
HIV: Viral infection that attacks the immune system by destroying white blood cells
- Replicates via Lysogenic cycle
- Develops into AIDs once the virus replicates
How are viruses transmitted?
- Human to Human
- Dust or water particles in the air (ex. measles, common cold)
- Contaminated water/food (ex. Cholera)
- Animal/insect bite (ex. rabies, West Nile)
- Insect bodies (ex. typhoid)
Lytic Virus cycle steps
- Bacteriophage attack to bacteria
- DNA injected into host
- Making virus parts
- Assembling virus parts
- Cell explodes- releasing viruses
Which cells work as part of the immune system?
Epithelial cell
Macrophages
Killer T-cells
Helper T-cells
B-cells
Memory Cells
Describe an immune response.
- Epitheal cells are infected, so they call for help by releasing chemicals
- Macrophages engulf the invader through the process phagocytosis. If more help is needed, they alert T-cells by releasing chemicals
- Helper T-cell send chemical messages that replicate Killer T-cells and B-cells
- Killer T-cell use antigens to differentiate between healthy cells and infected cells, destroying infected cells by releasing cytotoxins
- B-cells make proteins called antibodies that trap specific invaders in large clumps to be engulfed by macrophages.
Cancer
Cancer - Uncontrolled cell growth
Causes:
- Mutation in Proto-oncogenes
- Mutation in Tumer surpressing genes
DNA (Deoxyribonucleic Acid)
Function: Stores information that cells need to developand replicate
Structure: 2 strands, made of subunits called Nucleotides; 1 of 4 nitrogen bases (A-T C-G), phosphate group, & deoxyribose sugar.
*Phosphate group + deoxyribose = nucleoside/DNA backbone
Where is DNA located in Eukaryotes? Prokaryotes?
Eukaryotic - nucleus
Prokaryotic - cytoplasm
What is the shape of DNA?
Double Helix
Who took the first pictures of DNA? Who developed the DNA model?
Rosalind Franklin took 1st picture of DNA.
James Watson & Francis Crick discovered/developed the first DNA model.
Subunit of DNA.
Subunit of DNA is a Nucleotide. Nucleotides are made of 1 of 4 nitrogen bases (Thymine, Adenine, Guanine, & Cytosine), phosphate group, and deoxyribose sugar.
What type of bonds hold together the nitrogen bases of DNA? The phosphate and deoxyribose backbone?
Weak hydrogen bonds hold together nitrogen bases.
Covalent bonds hold together the backbone made of phospate and deoxyribose.
Differentiate purines and pyrimidines.
Purine: Adenine & Guanine- double rings
Pyrimidines: Cytosine, Thymine (DNA only), & Uracil (RNA only)- single rings
Purines always pair with Pyrimidines.
4 bases in DNA
(- is pairing)
Adenine - Thymine
Cytosine - Guanine
Complimentary DNA & mRNA sequence to:
CTAGCCA
DNA - GATCGGT
mRNA - GAUCGGU
Steps of DNA replication
- Helicase (enzyme) breaks DNAβs weak hydrogen bonds into two lines of nucleotides
- DNA polymerase (enzyme) aligns line of nucleotides to other nucleotides from nucleoplasm
- Weak hydrogen bonds link nitrogen bases & covalent bonds link the phasphate groups with deoxyribose sugars to make back bone of DNA
- Enzymes proof read for errors and make corrections (errors = mutations)
Result: Two identical double helixβs of DNA
Why do cells need to replicate their DNA?
So both daughter cells have genetic material (instructions) to function
Why would the body need to make new cells?
- Growth
- Repair
- Regeneration
Enzymes in DNA replication
- Helicase (enzyme) breaks DNAβs weak hydrogen bonds into two lines of nucleotides
- DNA polymerase (enzyme) aligns nucleotides from old DNA to new nucleotides
- Enzymes proof read for errors and make corrections (errors = mutations)
During which phase of the cell cycle does DNA Replication occur?
S-Phase of Interphase
What two processes are made possible because of DNA Replication?
Cell Cycles Mitosis & Meiosis
What are the three types of RNA and what is their structure, role, and location in cell?
mRNA (messanger RNA)
- Carries DNA code from nucleos/cytoplasm to ribosome to make proteins
- Single strand made of 1 of 4 nitrogen bases (A, U, C, G), phosphate group, & ribose
tRNA (transfer RNA)
- Carries amino acid mRNA codes for; pairs itβs anti-codons with mRNA codons
- clover leaf made of RNA nucleotides and amino acid
rRNA (ribosomal RNA)
- Clamps onto mRNA and uses its info to assemble amino acids
- Folds proteins into specific shape based on function
- Makes up ribosomes
Steps of Protein Sythesis
TRANSCRIPTION
1. Helicase (enzyme) uncoils/unzips DNA
2. RNA polymerase (enzyme) recognizes the uncoiled nucleotides and brings RNA nucleotides from the nucleoplasm
3. New ribose and phosphate backbone is formed
4. DNA and RNA strand (mRNA) seperate
TRANSLATION
1. mRNA leaves nucleus for ribosome
2. mRNA moves through ribosome until paired with START codon (AUG)
4. Anti codons on tRNA pair with complementary bases on codons on mRNA, & Amino acids at other end of tRNA form peptide bonds
6. tRNA continues pairing until mRNA codes for STOP codon (UAG, UGA, UAA)
7. rRNA folds protein based on function
Result: Protein
Transcription & Translation
Transcription - DNA code is copied to mRNA
Translation - mRNA codes for tRNAβs amino acids that form proteins
4 bases in RNA
Adenine - Uracil
Cytosine - Guanine
Complimentary mRNA sequence to CTAGCCA.
GAUCGGU
Codons & Anti-codons
Codons - Group of 3 nitrogen bases on mRNA
Anti-Codons - Group of 3 nitrogen bases on tRNA
What amino acids code for the sequences CGA GCC AUA?
-Use codon chart
CGA - Arginine
GCC - Alanine
AUA - Isoleucine
Gene mutations and Chromosomal mutations
Chromosomal mutations - change in large piece of chromosome
Gene mutations - change in DNA sequence in one gene of the chromosome
Types of gene mutations
Point Mutations - 1 nitrogen base is replaced = 1 amino acid changes
Framshift Mutations - 1 nitrogen base is deleted or added causing entire chain to shift = ALL amino acids change
Types of chromosomal mutations
Deletion - Part is deleted
Insertion - Part is added
Inversion - Sequence is flipped
Translation - Part is transferred between chromosomes
Adult/somatic stem cells vs. Embryonic stem cells
Embryonic Stem Cells - forms 4-5 days after fertilization and can turn into ANY cell
Adult/somatic Stem Cells- can turn into SOME cells
Provirus
stage in virus cycle where the virus is inactive in a host cell, producing only a few viruses at a time; cells function normally but can infect others
Influenza
- Viral infection that infects the sinuses/respiratory system
- Replicates via lyctic cycle
- Mutates a lot causing many strains
Smallpox
- Viral infection
- Passed by sneezing and coughing
- Eradicated in 1980 because of itβs 40% kill rate
Lysogenic Virus Cycle steps
- Bacteriophage attach to bacteria
- DNA injected into host
- Viral DNA incorporated into plasmid
- Viral DNA replicates with cell division
- Viruses are constructed
- Cells explodes- releasing viruses
Why are there not vaccines available for all viruses?
Viruses mutate to quickly before one is made (ex. common cold)
Bacteriophage
Virus that attacks bacteria
What is the immune response to an invader that has previosly infected the body?
Before the invader can replicate for long, memory cells recognize the virus from previous exposure as an invader, activate memory B-cells and memory T-cells that act as B-cells and T-cells, but more efficient because more antibodies are produced.
Backbone of DNA
Phosphate group & deoxyribose linked by covalent bonds
How can organisms be different from each other if their genetic material is made of nucleotides? (What makes you genetically different than a giraffe)
sequences of bases & quanity of genetic material
What is uncoiled and coiled DNA in the nucleos?
Coiled DNA = Chromosomes
Uncoiled DNA = Chromatin
What is the origin of each strand in the replicated DNA?
one strand is new
one strand is old
DNA Complementary bases of CAAGTC
GTTCAG
DNA controls the production of ______
Proteins
DNA is a polymer. Define Polymer.
Molecule made of many small pieces called monomers
How do you know if two organisms are closely related?
sequence and quanity of bases
START & END codons
Start = AUG
End = UAG, UGA, UAA
Why can mRNA leave the nucleus but DNA canβt?
mRNA is single stranded, DNA is double stranded
How can only 20 amino acids be made into all the proteins organisms need?
Sequence & Quanity
Mutations in ____________ are NOT passed onto offspring. Only affect offspring if in ____________.
Somatic/body cells;
sex/gamete cells
DNA & RNA
DNA
Strands - 2
Sugar - Deoxyribose
Bases - A-T C-G
RNA
Strands - 1
Sugar - RIbose
Bases - A-T C-G
Cell Fission
Asexual reproduction; division of parent cell into two daughter cells
Body/somatic cells vs. Sex cells
Body/Somatic cells
Γ· by mitosis
46 chromosomes
Sex Cells
Γ· by meiosis
23 chromosomes
Chromatin vs. Chromosomes
Chomatin - uncoiled strands of DNA
Chromosomes - coiled strands of DNA made of two chromatids and a centromere
Chromosomes are counted by there ______________.
CENTROMERE (ex. 46 chromosomes with only one chromatid + one centromere would still be 46 chromosomes)
Homologous chromosomes
2 chromosomes (pair) with the same info
Diploid vs. Haploid
Diploid - cell contains 2 sets of chromosomes (46 chromosomes) = body cells
Haploid - cell contains 1 set of chromosomes (23 chromosomes) = sperm/egg
What are the steps of Interphase?
G1 (Gap 1-growth) phase - increases size and prepares to replicate DNA
S-(Synethsis) phase - replicates DNA, having 2 sets of chromosomes, NO errors
G2 (Gap 2-growth) phase - Continues to grow
Acroynm for Mitosis steps
Prophase
Metaphase
Anaphase
Telophase
In mitosis in plants, the cytoplasm pinches and a ______ ______ is formed between both plant cells.
Cell Plate
Apoptosis
Programmed cell death, process that eliminates unneccassary cells to differentiate, or initiate cell death.
What is the purpose of checkpoints in the cell cycle?
Checks for errors, so erroes donβt develop into things like cancer
Cell Cycle regulators
Proteins that control the progression of a cell through the cell cycle, either stimulates or ends cell cycle:
-Stimulating proteins are proto-oncogenes. Mutations make Oncogenes that increase stimulation causing to much cell division.
-Inhibitory proteins are tumor supressor genes. Mutations make them unable to work, causing no slowing down.
