BIO REVIEW

What do protein signals control?

cells as they progress through the cell cycle

-Some promote, some inhibit cell division

Ex: cyclins

Job of a Protein: Internal Responses

Biochemical time clocks, keeps stages in order

Job of a Protein: External Responses

-Stop or Go signals for cell division

-Ex: wounds growth spurts, sufficient cell density signals

Apoptosis

-Cell "suicide" (another way for cells to regulate themselves)

Apoptosis is.....

Pre-Determined

Ex: webbing between digits of embryos, reabsorbtion of tail in humans

"abort" signal

Apoptosis

-damaged cells prevent transmission of damage

Cancer

-unregulated rapid cell division

What occurs with Cancer?

-several mutations to cell division regulating genes

-Remember: Genes code for Proteins

Tumor

mass of cells that don't do their orginal job

-crowds out the noral cells that do their job

Most cells:

quickly dies if out of place

(Cancer cells do not)

Metastasis

cancer cells breaking off from the primary tumor

-distributed to new parts of the body by the blood or lymph

-verb: to metasized

-noun: metastasis

Why can a tumor in a seemingly harmless place (like the skin) end up being fatal?

-Cancer cells or tumors in organs or the bloodstream can disrupt organ function

What do cancer cells do?

destroy healthy cells in organs, block their nutrient or oxygen supply, and allow waste products to build up

What happens if cancer becomes severe?

it can impair or prevent vital organ functons, result in death

Traditional Treatments of Cancer

-surgical removal

-chemotherapy

-radiation

Newer Therapies of Cancer Treatments

-targeting unique needs of cancer

-targed to specfic cancers

-boosting out body's own immune response

most cells \_________ and make cells \____________ like them

-divide

-exactly

How do organisms become fully formed from the embryo?

cell differentiation

Differentiation

process in which cells become specialized in structure and function

totipotent

cell that is able to develop into any type of cell in the organism

-Ex: first cells in the zygote

pluripotent

cell that is able to become most cells of that type of organsim

-Ex: Blastocyst (4+ days after conception)

Multipotent

cell that is able to become multiple cell types

-Ex: Bone marrow cells that develop into blood cells

all cells in an organism have.....

the same DNA

-regardless of type of cell (except sperm & eggs)

all cells differentiate by.....

biochemical signals that trigger the cells in certain body areas and body tissues to shut down portions of DNA

-only the genes needed for specific job of that cell type

3 types of stem cells

embryonic, adult, induced pluripotent

early embryonic cells are.....

totipotent

-embryo is destoryed in the process of harvesting

-obtained from already aborted embryos

-banned for federally funded research

Who banned embryo stem cell research?

President Bush and President Trump

Who lifted the ban on embryo stem cell research?

President Obama and President Biden

What does stem cell research help with?

1. further understanding of how cells differentiate and operate

2. Replace damage tissues

3. Grow Replacement organs (not enough organ donations avaliable to meet demand, reduces chances of organ rejection after transplant, reduce need for anti-rejection drugs)

4. Slow/reverse aging and treat diesease

Stem cell research possibilities

increase understanding of how diesease occur

-researchers understand how dieseases/conditions develop

Stem Cell research controversy

consideration of ethics of research involving the development/use of human embryos (mainly focuses on embryonic stem cells)

3 factors that keep cells small

-DNA (does not increase when a cell icnreases its size)

-Enchanging materials

-Surface Area/Volume (cell divides when are materials are used up, exchanging with wastes)

Why do cells have to be small?

to properly function

what happens if a cell becomes to large?

-information overload

-cells have greater demands on DNA, DNA can't always serves the needs of the growing cell

asexual reproduction

productions of genetically identical offspring from a single parent

sexual reproduction

offspring produced that inherit some genetic information from each parent

Advantages of asexual reproduction

-survival strategy (fast reproduction)

-idential offsprng (favorable condtions)

advantages of sexual reproduction

-species in environments (seasonal changes affect weather/food)

-genetic diversity (offspring have different characteristics to survive)

yeast production

unique

-they can reproduce sexually or asxually

-moslty reproduce asexually

levels at which DNA coils itself

1. Duplicated Chromosome

2. Supercoils

3. Histone Proteins

4. Nucleosome

5. DNA Double Helix

cell cycle

total of all a cells life stages

-cell grows, prepares for division, divides to form 2 daughter cells

name of prokaryotc cell division

binary fission: form of asexual reproduction

interphase

"in-between" period of growth of a cell (seperated fro cell divisions)

parts of interphase

G1, S, G2

"G": gap

"S": synthenize

G1

cells increase in size & synthenize new proteins and organelles

S

new DNA is replicated

G2

organelles and molecules required for cell division are produced

M Phase

where cell division occurs (not included in interphase)

-2-step proces: mitosis and cytokinesis

mitosis

division of cell nucleus

cytokinesis

division of cytoplasm

why do chromosomes need to duplicate themselves before mitosis?

so that each daughter cell will have a complete copy of the genetic material from the parent cell

Stages of mitosis

1. Prophase

2. Metaphase

3. Anaphase

4. Telophase

prophase

duplicated chromosomes contain chromatids which are then divided/seperated between the daughter cells

-cell starts to build a spindle