Biology - The TREQUEL

Why must your cells activate specific genes to respond to some signals (ligands)?

The genes allow the cell to produce the proper protein and specialized RNA to respond to the signal

your genes contain the instructions to make which two types of biological molecules?

- amino Acid sequence of a specific protein (polypeptide)

- ribonucleotide sequence of a specialized RNA molecule

which organelles contain the genes of the human genome?

nucleus and the mitochondria

does DNA contain your genes?

yes

do chromatin molecules in the nucleus contain your genes?

yes

the nucleotide sequence of a protein-coding gene determines the ________ of the protein it encodes

amino acid sequence

the nucleotide sequence of a gene that codes for a specialized RNA molecule determines the _______ of the RNA it encodes

ribonucleotide sequence

are genes located on the crick strand, the watson strand, or on both strands?

both DNA strands contains genes

which part of a eukaryotic gene contains the information to recruit the enzymes and proteins necessary to activate the gene

promoters

which part of a eukaryotic gene contains the information to instruct the cell where to stop reading

transcription stop site

which part of a eukaryotic gene contains the information to instruct the cell where to stop reading

transcription stop site

what information does the nucleotide sequence of the coding region of a protein-coding gene contain

the amino acid sequence of the protein

do the exons or introns determine the amino acid sequence of the protein the gene encodes

exons

why is mitotic cell division essential for single-cell eukaryotes?

used to reproduce and generate an exact replica of a single cell organism

also used to purge toxic substances into daughter cell which is reproduced

why is mitotic cell division essential for multi-cell eukaryotes?

growth, repair, renewal of older or malfunctioning cells, helping immune system

which nucleic acid and proteins interact to form chromatin?

DNA and the histone protein

where is chromatin located in the eukaryotic cell?

nucleus

what are some functions of chromatin?

positions DNA properly in the nucleus

- involved in nuclear envelope synthesis

- contributes to the precise regulation of gene expression

- reduces the mutation rate DNA to preserve gene integrity

- It packages the DNA molecules into a shortened form that will fit in the nucleus

why must DNA replication occur before the mitotic phase

there would only be DNA for one daughter cell not both

why must each daughter cell receive 46 chromosomes and a complete set of organelles

so the daughter cells can function properly and act independently

what is the purpose of mitosis

mitosis allows all eukaryotic cells to reproduce

what is the purpose of cytokinesis

it separates the adult stem cell to produce two daughter cells; replenishes the amount of cells

when do the chromatin molecules condense into the chromosomes

prophase

when is spindle formation complete

prophase

when does the nuclear envelope disassemble and microtubules attach to the kinetochore

prophase and pre-metaphase

when does the spindle separate each pair of sister chromatids and deliver each chromosome to opposite ends of the cell

anaphase

when do the chromosomes unwind to reform the chromatin molecules

telophase

when does the nuclear envelope reform around the 46 chromatin molecules at each end of the cell

telophase

what is the function of the spindle during mitosis

the spindle coordinates the movement of the chromosomes during mitotic cell division

which protein filaments form the spindle

microtubules

which proteins polymerize to form the spindle microtubules

tubulins

the kinetochore forms at which DNA sequence of each sister chromatid

centromere DNA sequence

the spindle microtubules attach to which site on each sister chromatid

kinetochore

do motor proteins enable the kinetochore to move along the spindle microtubules in anaphase

motor proteins (dynein and kinesin)

can spindle checkpoint failure cause aneuploidy, increase cancer risk, or increase aging rate

yes (nondisjunction)

yes, suppressing of parts of the immune system that decreases cancer risk

yes, suppressing of parts of the immune system so aging increases

your adult stem cell completes mitosis but not cytokinesis.

- how many total chromosomes are in the cell?

- are there one or two nuclei in the cell?

there would be 2 nuclei and 2 groups of 46 chromosomes (92)

what are the defining characteristics of cancer cells

the ability to reproduce indefinitely due to defective mitotic cell division

- a defective cell control system due to one or more inactivated cell cycle checkpoints

- the inability to self-destruct by apoptosis

- abnormal binding properties

why do cancer cells in a single tumor have different characteristics

a single tumor contains cancer cells with distinct characteristics due to different mutations in different cancer cells

why do cancer cells in a single tumor often respond differently to chemotherapy

the mutations in some cancer cells can make a tumor more resistant than normal cancer cells

why do cancer cells ignore one or more cell cycle checkpoints

the cell division process is unregulated

what is a malignant tumor and why is it potentially lethal

malignant tumors often contain cancer cells that metastasize to form new tumors which can be located at important parts of the body

which type of tumor contains cancer cells that metastasize

malignant tumors

what is a benign tumor

tumors that contain cancer cells that cannot metastasize and cannot invade new locations in the body to form additional tumors

how can benign tumors pose a significant health threat

benign tumors can cause problems by their size, location, and ability to affect bodily processes

what is chemotherapy

treatment of cancer, infectious diseases, or genetic disorders by use of pharmaceuticals

how does cancer chemotherapy affect the cancer patient's adult stem cells

- prevents mitotic cell division

- inhibits nucleotide synthesis

- inhibits spindle function

- induces apoptosis

what are some side effects of anti-hormone therapy in women

prevents the synthesis of estrogen and progestin in women

what are some side effects of anti-hormone therapy in men

prevents the synthesis of androgen

which anti-cancer drugs inhibit spindle function

drugs derived from plants

- colchicine, paclitaxel, vinblastine, vincristine

which anti-cancer drugs inhibit nucleotide synthesis and DNA replication

methotrexate and hydroxyurea

- block cancer cells from synthesizing an adequate supply of nucleotides necessary for DNA synthesis

which anti-cancer drugs inhibit angiogenesis

angiostatin and avastin

- starve cancer cells by depriving them of substances for survival

how does the inhibition of angiogenesis harm cancer cells

as a tumor grows, its demand for glucose, amino acids, and oxygen grows

chemotherapy damages blood supply to the tumor.

what are telomeres

the "protective caps" located at the ends of linear DNA molecules

what is the essential cellular function of telomeres

telomeres prevent the loss of genes at the ends of the linear DNA molecules

what enzyme makes telomeres

telomerase synthesis during the S-phase

how does radiation therapy result in cancer cell destruction

radiation is used to strike the cancer cells causing mutations and damage to the DNA which could eventually lead to apoptosis

how do the vaccines, Cervarix and Gardasil, prevent some cancers caused by HPV

it allows for the immune system to recognize and eliminate HPV before it infects its host cells and transforms them. to cancer cells

why is it essential to vaccinate young people against HPV prior to HPV infection

the vaccine is only effective before an HPV Infection occurs

how do small, hydrophobic, and nonpolar molecules cross the cell membrane

simple diffusion

which energy source drives the facilitated diffusion of small, hydrophilic substances across the cell membrane

the concentration gradient

what do channel proteins transport

channel proteins allow for small, hydrophilic ions and water molecules to pass through the membrane

what to carrier proteins transport

carrier protein allows for large hydrophilic molecules (amino acids, monosaccharides, and nucleotides)

is each channel protein and carrier protein specialized to transport a specific, small, hydrophilic substance

yes, they are specific for each molecule

does the facilitated diffusion of lactose or amino acids require a channel protein or carrier protein

carrier protein (hydrophilic and large)

does the facilitated diffusion of potassium ions require a channel protein or carrier protein

channel protein (hydrophilic and small)

does the facilitated diffusion of water require a channel protein or carrier protein

channel proteins (aquaporins)

what is an aquaporin

channel proteins for water to pass through

which energy source do active transport proteins require

adenosine triphosphate (ATP)

do active transport proteins move substances across the cell membrane from high to low or low to high concentrations

low to high concentrations (against the gradient)

which active transport proteins enable cancer cells to export anti-cancer drugs

multidrug resistance proteins

which active transport proteins enable pathogenic bacteria to export antibiotics

multidrug resistance proteins

define diffusion

spontaneous movement of a substance from an area of higher concentration to lower concentration until it reaches equilibrium

how do your cells use diffusion to support the facilitated diffusion across the cell membrane

they use the energy of diffusion to move particles across the cell membrane from high to low concentrations

what are vesicles

membranous sacs that are used to transport materials in the cell

how do the beta cells of the pancreas simultaneously export multiple copies of insulin stored in vesicles

beta cells use exocytosis to release copies of insulin

which process enables cancer cells to export multiple copies of the growth factor stored in vesicles to stimulate angiogenesis

active transport using an abnormally high number of multidrug resistance proteins

why do your cells require endocytosis

some substances are to large to transport by active or passive transport processes

which type of endocytosis imports dissolved substances (solutes) in the extracellular fluid

pinocytosis

what are some functions of pinocytosis

cellular drinking and a process by which lipid droplets are ingested by living cells and engulf external substances, gathering them into special membrane vesicles contained within the cell.

what is the function of receptor-mediated endocytosis

imports large, specific particles by using receptors that recognize a certain substance

what particles does receptor-mediated endocytosis import

- lipoproteins

- signal hormones

- transferrin

what enables your macrophages to import bacteria and viruses for destruction

phagocytosis

which three types of protein filaments form the cytoskeleton

- actin filaments (microfilaments)

- intermediate filaments

- microtubules

which motor proteins use the energy of ATP to move along the microtubules

dyneins

which motor proteins use the energy of ATP to move along the actin filaments

myosins

how do the motor proteins attach to the substances they transport in the cell

interact with the actin filaments and microtubules along the cytoskeleton

define an allele

different versions of a single gene

define a mutation

change in the nucleotide sequence of DNA molecules or RNA genomes

define a loss of function mutation

inactivates the tumor suppressor genes

define a gain of function mutation

converts proto oncogenes into oncogenes

define a mutagen with the three different types

biological, chemical, or physical agents that cause mutations

what are the 3 types of mutagens

- radiation (UV)

- chemicals (carcinogens)

- infectious Agents (bacteria)

define a carcinogen

a mutation that causes a mutation that causes cancer

carcinogens cause cancer by inducing mutations in which two gene families

proto oncogenes and tumor suppressor genes

what is the normal role of the proto oncogenes in cell cycle regulation

code for proteins to stimulate the cell cycle and mitotic division in a precisely controlled environment

proto oncogenes code for which proteins

proteins that stimulate the cell cycle and proteins that are the gas pedals/accelerators of the cell cycle

what are the functions of the proteins coded by proto oncogenes

they stimulate the cell cycle and mitotic cell division in a precise, controlled manner

which type of mutation converts a proto oncogene to an oncogene

gain of function mutation

why does one copy of an oncogene significantly increase the risk of cancer

the oncogene stimulates mitotic cell division in an unregulated manner

what is the normal role of the tumor suppressor gene in cell cycle regulation

ensure the accuracy of the cell cycle and the accuracy of mitotic cell division