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
——
𝑹𝒆𝒔𝒖𝒍𝒕: 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 DNA’s 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 helix’s 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 DNA’s 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 it’s 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