Biology 4

Front 1

How can we tell the differences in DNA between two people?

Back 1

Answer: People may have the same gene but of slightly different sizes
Technique to show differences in size = gel electrophoresis

Front 2

How can we get enough DNA to do gel electrophoresis?

Back 2

Answer: Use the way the cell normally copies DNA during S-phase (Replication)
Technique to copy specific pieces of DNA = PCR

Front 3

Covalent Bonds

Back 3

Between sugar and phosphate

Front 4

Hydrogen Bonds

Back 4

Between two phosphates (G-C or A-T)

Front 5

Replication

Back 5

Strands separate...Each strand now serves as template for synthesis of a separate DNA molecule as free nucleotides base-pair with complementary nucleotides on the existing strand

Front 6

Helicases

Back 6

unwind DNA double helix

Front 7

Helicases

Back 7

unwind DNA double helix

Front 8

Primase

Back 8

makes a starting point (primer)

Front 9

DNA polymerase

Back 9

connects new complementary bases

Front 10

Ligase

Back 10

attaches pieces together

Front 11

PCR (Polymerase Chain Reaction)

Back 11

Step 1: Denaturation – high heat causes the 2 strands to separate
Step 2: Annealing: Primers target a specific sequence and initiate DNA replication – one in each direction
Step 3: Extension: DNA polymerase elongates the copied strand
Each cycle doubles the # of copies of DNA

Front 12

Info

Back 12

We can use the amelogenin gene to determine the sex of a blood sample.
Male: XY: two different versions, two lines on the PCR sample
Female: XX: same version, one line on the PCR

Front 13

DNA fingerprints

Back 13

Short Tandem Repeats (STRs)
Different people have different numbers of repeats on their chromosomes

Front 14

cancer v tumor

Back 14

Cancer is a disease that eventually disrupts body functions whereas a tumor is a mass of cells with no apparent function in the body

Front 15

cancer

Back 15

cancer is a group of diseases characterized by uncontrolled growth and spread of abnormal cells. If the spread is not controlled, it can result in death

Front 16

tumors

Back 16

Two types:
Benign (non-cancerous) – this is not cancer!
Does not spread; it can eventually become malignant in some cases
Malignant (cancerous) – this is cancer!
Has the potential to spread to other parts of body

Front 17

metastatic

Back 17

if individual cells break away and start a new tumor elsewhere

Front 18

Why does cancer primarily affect older people rather than young people?

Back 18

Because the immune system of old people is not as effective in distinguishing normal cells from cancer cells
B: Because old people have been exposed to more carcinogens
C: Because cancer develops after multiple mutations have occurred which takes years to happen

Front 19

The cell cycle has four phases and controls cell division

Back 19

Two Gap or Growth phases (G1 and G2)
S phase - DNA synthesis
M phase - Mitosis

Front 20

Cell Cycle Checkpoints

Back 20

Three checkpoints in cell cycle
G1-S transition
G2-M transition
Exit M phase transition
Checkpoints are where the cell has an opportunity to assess whether conditions are favorable for cell division
A protein called p53 can stop the cell cycle when a cell’s DNA is damaged and induce the cell to die

When the proteins that regulate the cell cycle are mutated or absent then cells can divide out of control leading to cancer

Front 21

Cell Cycle Checkpoints

Back 21

Three checkpoints in cell cycle
G1-S transition
G2-M transition
Exit M phase transition
Checkpoints are where the cell has an opportunity to assess whether conditions are favorable for cell division
A protein called p53 can stop the cell cycle when a cell’s DNA is damaged and induce the cell to die

When the proteins that regulate the cell cycle are mutated or absent then cells can divide out of control leading to cancer

Front 22

Cell Cycle Checkpoints

Back 22

Three checkpoints in cell cycle
G1-S transition
G2-M transition
Exit M phase transition
Checkpoints are where the cell has an opportunity to assess whether conditions are favorable for cell division
A protein called p53 can stop the cell cycle when a cell’s DNA is damaged and induce the cell to die

When the proteins that regulate the cell cycle are mutated or absent then cells can divide out of control leading to cancer

Front 23

Cell Cycle Checkpoints

Back 23

Three checkpoints in cell cycle
G1-S transition
G2-M transition
Exit M phase transition
Checkpoints are where the cell has an opportunity to assess whether conditions are favorable for cell division
A protein called p53 can stop the cell cycle when a cell’s DNA is damaged and induce the cell to die

When the proteins that regulate the cell cycle are mutated or absent then cells can divide out of control leading to cancer

Front 24

From Benign to Malignant

Back 24

Cancer cells divide quickly and can leave the original site and enter the blood, lymph or tissues
Most cells divide a set number (60-70) of times, then they stop dividing
This usually limits benign tumors to small sizes
Cancer cells can divide indefinitely

Front 25

How do cancer cells travel through the human body?

Back 25

The lymphatic system collects fluids lost from capillaries and with it cancer cells, which are then delivered elsewhere through the circulatory system

Front 26

Gardasil

Back 26

works against 4 strains of human papilloma virus (HPV), 2 for genital warts, 2 for cervical cancer.
Gardasil is 100% effective for 4 years; but it must be given before exposure to the virus.
Overall, an estimated 75% of sexually active individuals will be exposed to HPV in their lives.

Front 27

Gardasil

Back 27

works against 4 strains of human papilloma virus (HPV), 2 for genital warts, 2 for cervical cancer.
Gardasil is 100% effective for 4 years; but it must be given before exposure to the virus.
Overall, an estimated 75% of sexually active individuals will be exposed to HPV in their lives.

Front 28

HPV Types

Back 28

Over 100 different HPVs have been identified in humans, HPV2 causes common warts.
All infect through epithelial cells in the upper skin (via any skin-skin contact, hands included.)

Front 29

HPV Reproduction

Back 29

Step 1 Makes RNA:Transcription
Step 2:Makes Protein:Translation

Front 30

HPV Infection

Back 30

Along with lacking replication enzymes HPV do not have the ability to burst the cell that they have infected. So, HPV must invade a cell that is actively dividing and can only be released when the cell dies and lyses as is the normal process in production of the outer keratinized layer of skin. Basal cells are the only cells in the epidermis that are actively dividing, so infection must occur in these cells (through micro-abrasions)

Front 31

step 1- transcription

Back 31

RNA is copied using the DNA as a template
RNA: copy of DNA travels out of nucleus into cytoplasm
RNA: A=U C=G

Front 32

RNA Differs from DNA

Back 32

RNA is single-stranded, NOT DOUBLE HELIX
ribose is 5 carbon sugar in RNA
uracil (U) replaces thymine (T)

Front 33

Three Types of RNA

Back 33

mRNA (messenger RNA) copy of genes used to make proteins
tRNA (transfer RNA) used in synthesis of proteins
rRNA (ribosomal RNA) used in synthesis of proteins, part of the ribosome.

Front 34

HPV Vaccines

Back 34

A vaccine is an preparation used to produce to a disease, in order to prevent or ameliorate the effects of infection by any natural or "wild" strain of the organism

Front 35

Antigen

Back 35

any protein from a pathogen that the immune system recognizes.

Front 36

Antibodies

Back 36

proteins created by B cells that bind to antigens and kill the pathogen

Front 37

antigens and antibodies

Back 37

Exposure to the antigen stimulates antibody-producing B cells to divide and create long-lived memory cells that keep making antibodies for decades.
Antibodies bind to the antigen and target it for destruction.

Front 38

Types of Vaccines

Back 38

Traditional
Live attenuated- less virulent pathogen (MMR)
Inactivated- killed with heat or chemicals (flu)
Toxoid- inactive toxic compounds (tetanus)
New
Recombinant- produce protein in bacteria or insect cells by introducing the gene.

Front 39

vaccine with its problems

Back 39

Live Attenuated-Actual infection though weak may harm many, but proteins antigens unaltered.
Inactivated--No infection risk (dead), but heat used to kill it may have altered protein antigens
Recombinant--No infection risk (only pure protein antigen injected), but have to clone gene to get bacteria to produce it.

Front 40

Creating Recombinant DNA

Back 40

Step 1: PCR gene
Step 2: restriction digestion of DNA
Step 3: ligation of DNA
Step 4: infect insect cells

Front 41

Creating Recombinant DNA

Back 41

Step 1: PCR gene
Step 2: restriction digestion of DNA
Step 3: ligation of DNA
Step 4: infect insect cells

Front 42

Step 1- PCR Gene

Back 42

1- Denature DNA
2- Anneal primers
3- Extend primers to copy DNA

Front 43

Step 2- Restriction Enzymes

Back 43

Restriction Enzymes isolated from bacteria used to cleave DNA
Each enzyme cuts at a specific sequence, often palindromic
Leave “sticky ends” with complementary base pairs