In many types of cancer, proteins that are crucial regulators of the cell cycle are often mutated and cannot function correctly. This leads to the evasion of apoptosis and to the loss of control of cell proliferation? For example, many cancer cells carry two mutant copies of the gene that codes for a tumor suppressor protein named p53. What is the normal function of p53 that is lost when it is mutated?

In many types of cancer, proteins that are crucial regulators of the cell cycle are
often mutated and cannot function correctly. This leads to the evasion of apoptosis
and to the loss of control of cell proliferation? For example, many cancer cells carry
two mutant copies of the gene that codes for a tumor suppressor protein named p53.
What is the normal function of p53 that is lost when it is mutated?
by

1 Answer

Answer :

Normally, p53 senses DNA damage and acts as a transcription factor for checkpoint
control genes.
by

Related questions

True statements about p53 include: a. a protein coded by a tumour suppressor gene b. it suppresses mitosis c. it is important regulators of apoptosis d. all above

Description : True statements about p53 include: a. a protein coded by a tumour suppressor gene b. it suppresses mitosis c. it is important regulators of apoptosis d. all above

Last Answer : all above

In order to function, CDKs must interact with members of a separate family of proteins named the cyclins. Do individual cyclins remain associated with the same CDKs throughout the entire cell cycle?

Description : In order to function, CDKs must interact with members of a separate family of proteins named the cyclins. Do individual cyclins remain associated with the same CDKs throughout the entire cell cycle?

Last Answer : No. Separate cyclins interact with specific CDKs only during defined periods of the cell cycle.

Multiple checkpoints in the eukaryotic cell cycle ensure that division occurs only after sufficient growth and faithful DNA replication, and only when favorable conditions exist. Of the many proteins involved in cell cycle control, cyclin-dependent kinases (CDKs) are among the most important. How do CDKs function to control the cell cycle?

Description : Multiple checkpoints in the eukaryotic cell cycle ensure that division occurs only after sufficient growth and faithful DNA replication, and only when favorable conditions exist. Of the many proteins involved in ... CDKs) are among the most important. How do CDKs function to control the cell cycle?

Last Answer : CDKs phosphorylate various protein substrates that are required for cell cycle progression. Some of the important substrate proteins that CDKs phosphorylate include condensin proteins, which are essential ... which form a stabilizing network under the nuclear membrane that assembles during mitosis.

.E.coli cells with a mutated z gene of the lac operon cannot grow in medium containing only lactose as the source of energy because (a) the lac operon is constitutively active in these cells (b) they cannot synthesise functional beta galactosidase (c) in the presence of glucose, E.coli cells do not utilise lactose (d) they cannot transport lactose from the medium into the cell.

Description : .E.coli cells with a mutated z gene of the lac operon cannot grow in medium containing only lactose as the source of energy because (a) the lac operon is constitutively active in these cells ( ... coli cells do not utilise lactose (d) they cannot transport lactose from the medium into the cell.

Last Answer : (b) they cannot synthesise functional beta galactosidase

The eukaryotic cell cycle consists of discrete phases. One of these is named the M or mitosis phase during which the cell divides. Following the M phase is a period known as interphase that is made up of three distinct phases. Name, in order, the three separate phases of interphase.

Description : The eukaryotic cell cycle consists of discrete phases. One of these is named the M or mitosis phase during which the cell divides. Following the M phase is a period known as interphase that is made up of three distinct phases. Name, in order, the three separate phases of interphase.

Last Answer : G1, S and G2

If a woman developed skin cancer as result of a mutated gene in the skin cells of her arms could she pass skin cancer gene to her children justify your answer?

Description : If a woman developed skin cancer as result of a mutated gene in the skin cells of her arms could she pass skin cancer gene to her children justify your answer?

Last Answer : Need answer

A mutant strain of T4 - Bacteriophage, R-II, fails to lyse the E. coli but when two strains R-IIX and R-IIY are mixed then they lyse the E. coli. What may be the possible reason? (a) Bacteriophage transforms in wild. (b) It is not mutated. (c) Both strains have similar cistrons. (d) Both strains have different cistrons.

Description : A mutant strain of T4 - Bacteriophage, R-II, fails to lyse the E. coli but when two strains R-IIX and R-IIY are mixed then they lyse the E. coli. What may be the possible reason? (a) ... . (b) It is not mutated. (c) Both strains have similar cistrons. (d) Both strains have different cistrons.

Last Answer : (d) Both strains have different cistrons.

Lactose or its analogues act as positive regulators of lac operon by (A) Attaching to i gene and preventing its expression (B) Increasing the synthesis of catabolite gene activator protein (C) Attaching to promoter region and facilitating the binding of RNA polymerase holoenzyme (D) Binding to repressor subunits so that the repressor cannot attach to the operator locus

Description : Lactose or its analogues act as positive regulators of lac operon by (A) Attaching to i gene and preventing its expression (B) Increasing the synthesis of catabolite gene activator protein (C) ... holoenzyme (D) Binding to repressor subunits so that the repressor cannot attach to the operator locus

Last Answer : Answer : D

Cells must constantly manage metabolic pathways, and this is often done by balancing specific biochemical reactions within a pathway. For example, the metabolic product of one pathway may block the formation of that specific metabolite at an earlier point in the pathway to prevent a buildup of that specific product. What is this process called?

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Last Answer : Feedback inhibition

RNA is composed of strands of nucleotides that are read as a 3 nucleotide codon. These are distinguished by tRNAs that match the codons on one end and carry individual building blocks of a protein chain. What are these building blocks of protein that tRNAs bind?

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Last Answer : Amino Acids

Which of the following structure-function pairs is mismatched? (A) Lysosome-intracellular digestion (B) Golgi body-secretion of cell products (C) Ribosome-protein synthesis (D) Glyoxysome-detoxification

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Last Answer : (D) Glyoxysome-detoxification

Which of the following correctly matches an organelle with its function? (A) Mitochondrion . . . photosynthesis (B) Nucleus . . . cellular respiration (C) Ribosome . . . manufacture of lipids (D) Central vacuole . . . storage

Description : Which of the following correctly matches an organelle with its function? (A) Mitochondrion . . . photosynthesis (B) Nucleus . . . cellular respiration (C) Ribosome . . . manufacture of lipids (D) Central vacuole . . . storage

Last Answer : (D) Central vacuole . . . storage

What is the function of proteins like microtubules and actin filaments?

Description : What is the function of proteins like microtubules and actin filaments?

Last Answer : Give structure to cells.

Typically proteins do not work in their simple amino acid chain structure but instead fold and form shapes that help in their function. Which of the structures is described as being in alpha helices and beta sheets?

Description : Typically proteins do not work in their simple amino acid chain structure but instead fold and form shapes that help in their function. Which of the structures is described as being in alpha helices and beta sheets?

Last Answer : Secondary Protein Structure

Palliation refers to a) relief of symptoms associated with cancer. Palliation is the goal for care in terminal cancer patients. b) hair loss. Alopecia is the term that refers to hair loss. c) the spread of cancer cells from the primary tumor to distant sites. Metastasis is the term that refers to the spread of cancer cells from the primary tumor to distant sites. d) the lowest point of white blood cell depression after therapy that has toxic effects on the bone marrow. Nadir is the term that refers to the lowest point of white blood cell depression after therapy that has toxic effects on the bone marrow.

Description : Palliation refers to a) relief of symptoms associated with cancer. Palliation is the goal for care in terminal cancer patients. b) hair loss. Alopecia is the term that refers to hair loss. c) ... the lowest point of white blood cell depression after therapy that has toxic effects on the bone marrow.

Last Answer : a) relief of symptoms associated with cancer. Palliation is the goal for care in terminal cancer patients.

In human body, the cell growth and differentiation are highly controlled and regulated, but in cancer cells. (a) there is breakdown of these regulatory mechanism leading to formation of benign and malignant tumors (b) controlled cell division and over production of genetic material occur (c) RNA is mutated and produced in less amount (d) DNA is mutated and produced in less amount

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Last Answer : Ans:(a)

What types of proteins are involved in the packaging and condensing of DNA into tightly wound nucleosome structures of a chromosome?

Description : What types of proteins are involved in the packaging and condensing of DNA into tightly wound nucleosome structures of a chromosome?

Last Answer : Histone

Metabolism is carried out by a large class of proteins that decrease the activation energy required for chemical reactions inside a cell. Therefore they only facilitate reactions that would naturally occur at a much slower rate. What is the name of these proteins that speed up biochemical reactions?

Description : Metabolism is carried out by a large class of proteins that decrease the activation energy required for chemical reactions inside a cell. Therefore they only facilitate reactions that would naturally occur at a much slower rate. What is the name of these proteins that speed up biochemical reactions?

Last Answer : Enzymes

A cell that is missing lysosomes would have difficulty doing what? (A) Digesting food (B) Storing energy (C) Packaging proteins (D) Moving cytoplasm

Description : A cell that is missing lysosomes would have difficulty doing what? (A) Digesting food (B) Storing energy (C) Packaging proteins (D) Moving cytoplasm

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The three-dimensional network of protein filaments within the cytoplasm of eukaryotic cells is called the (A) Endoplasmic reticulum (B) Golgi apparatus (C) Cytoskeleton (D) None of these

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SER is abundant in cells that are involved in (A) Lipid metabolism (B) Protein metabolism (C) Glucose metabolism (D) Calcium metabolism

Description : SER is abundant in cells that are involved in (A) Lipid metabolism (B) Protein metabolism (C) Glucose metabolism (D) Calcium metabolism

Last Answer : (A) Lipid metabolism

Tissues are constructed from many distinct cell types that perform different functions in response to signals from each other and the extracellular matrix. During tissue development and tissue regeneration, stem cells serve as a reservoir of undifferentiated cells that have the capacity to mature into different cell types. What is the name of the process that stem cells undergo when they are required to generate a particular type of cell?

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What common cell types are regulated by ion channels and are commonly referred to as excitable cells?

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Which of the following types of lung cancer is characterized as fast growing and tending to arise peripherally? a) Large cell carcinoma Large cell carcinoma is a fast-growing tumor that tends to arise peripherally. b) Bronchioalveolar carcinoma Bronchioalveolar cell cancer arises from the terminal bronchus and alveoli and is usually slow-growing. c) Adenocarcinoma Adenocarcinoma presents as peripheral masses or nodules and often metastasizes. d) Squamous cell carcinoma Squamous cell carcinoma arises from the bronchial epithelium and is more centrally located.

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Last Answer : a) Large cell carcinoma Large cell carcinoma is a fast-growing tumor that tends to arise peripherally.

An important step in protein synthesis is transcription. Which of the following statement(s) is/are true concerning this process? a. The first step in gene transcription involves separating the double helix of DNA by an enzyme known as DNA polymerase b. The initial product of DNA transcription is called heterogeneous nuclear RNA which codes directly for proteins c. After processing is complete, the mRNA is exported from the nucleus to the cytoplasm d. Only one protein can be produced from an initial mRNA strand

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It is a mesh of interconnected membranes that serve a function involving protein synthesis and transport. (A) Endoplasmic reticulum B) Cytoskeleton (C) Golgi apparatus (D) Both A and B

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Last Answer : (A) Endoplasmic reticulum

In a eukaryotic cell, what separates DNA from the protein translation machinery in the cytoplasm?

Description : In a eukaryotic cell, what separates DNA from the protein translation machinery in the cytoplasm?

Last Answer : The nuclear envelope.

The door to your house is like the __________________ of a cell membrane? (A) Phospholipid bilayer (B) Integral protein (C) Recognition protein (D) Peripheral protein

Description : The door to your house is like the __________________ of a cell membrane? (A) Phospholipid bilayer (B) Integral protein (C) Recognition protein (D) Peripheral protein

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Are the levels of the cyclins constant throughout the cell cycle?

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Last Answer : No. Cyclins are synthesized only when required and then they are degraded by specific enzymes at defined times in the cell cycle.

Which of the following are regularly assembled and disassembled during cell cycle. (A) Microtubules (B) Intermediate filaments (C) Both A and B (D) None of these

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If a gene mutation prevents formation of an enzyme normally used by a lysosomes, a disease may result known as (A) Lysosomal abstracted disease (B) Lysosomal secretory disease (C) Lysosomal storage disease (D) All A, B and C

Description : If a gene mutation prevents formation of an enzyme normally used by a lysosomes, a disease may result known as (A) Lysosomal abstracted disease (B) Lysosomal secretory disease (C) Lysosomal storage disease (D) All A, B and C

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G-proteins: a. are activated by the binding of an extracellular ligand to a membrane receptor b. can be mutated in tumour cells c. mediate the action of glucocorticoid hormone d. they are inactivated by cholera toxins

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Last Answer : are activated by the binding of an extracellular ligand to a membrane receptor

MHC Class II proteins, in conjunction with antigens, are recognised by (A) Cytotoxic T cells (B) Helper T cells (C) Suppressor T cells (D) Memory T cells

Description : MHC Class II proteins, in conjunction with antigens, are recognised by (A) Cytotoxic T cells (B) Helper T cells (C) Suppressor T cells (D) Memory T cells

Last Answer : Answer : B

MHC class I proteins, in conjunction with antigens are recognised by (A) Cytotoxic T cells (B) Helper T cells (C) Suppressor T cells (D) Memory T cells

Description : MHC class I proteins, in conjunction with antigens are recognised by (A) Cytotoxic T cells (B) Helper T cells (C) Suppressor T cells (D) Memory T cells

Last Answer : Answer : A

Sodium ions are "pumped" from a region of lower concentration to a region of higher concentration in the nerve cells of humans. This process is an example of (A) Diffusion (B) Passive transport (C) Osmosis (D) Active transport

Description : Sodium ions are "pumped" from a region of lower concentration to a region of higher concentration in the nerve cells of humans. This process is an example of (A) Diffusion (B) Passive transport (C) Osmosis (D) Active transport

Last Answer : (D) Active transport

Which of the following statements is not true for retroviruses? (a) DNA is not present at any stage in the life cycle of retroviruses. (b) Retroviruses carry gene(c) The genetic material in mature retroviruses is RNA. (d) Retroviruses are causative agents for certain kinds of cancer in man. for RNA-dependent DNA polymerase.

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How do the rough endoplasmic reticulum and the Golgi apparatus act in the production and releasing of proteins ?

Description : How do the rough endoplasmic reticulum and the Golgi apparatus act in the production and releasing of proteins ?

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Without saturation of transport proteins and under same concentration gradient how can the speed of simple diffusion be compared to the speed of facilitated diffusion ?

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Last Answer : The action of facilitator proteins in facilitated diffusion makes this type of diffusion faster than simple diffusion under equal concentration gradients of the moved substance.

What are heterotrimeric G proteins?

Description : What are heterotrimeric G proteins?

Last Answer : G proteins with three different subunits, designated as alpha, beta, and gamma. Alpha and gamma subunits attach to the plasma membranes via lipid anchors. In the absence of a signal, the entire GDP ... alpha subunit is replaced by GTP, and the GTP-bound alpha subunit and beta-gamma dimer dissociate.

What are G proteins?

Description : What are G proteins?

Last Answer : G proteins are proteins that can bind guanosine triphosphate (GTP) and guanosine diphosphate (GDP). G-proteins function as switches; GTP-bound G-proteins are active whereas GDP-bound G-proteins are inactive.

True or False: The vast majority of mitochondrial proteins are synthesized from genetic information encoded in the mitochondrial genome.

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Name the organelle that contains high levels of hydrolases and is responsible for digestion of proteins, sugars, nucleic acids and lipids.

Description : Name the organelle that contains high levels of hydrolases and is responsible for digestion of proteins, sugars, nucleic acids and lipids.

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Describe how proteins that are synthesized in the endoplasmic reticulum (ER) are transported to their final destination.

Description : Describe how proteins that are synthesized in the endoplasmic reticulum (ER) are transported to their final destination.

Last Answer : Proteins that are synthesized in the ER have a signal sequence that directs them to their target destination. Soluble proteins are carried inside the lumen of vesicles. Cargo-bearing vesicles ... lysosomes or plasma membrane. Vesicles that have released their cargo return via the reverse direction.

Name the type of proteins that work to catalyze metabolic reactions or can modify other proteins to switch their activity on or off.

Description : Name the type of proteins that work to catalyze metabolic reactions or can modify other proteins to switch their activity on or off.

Last Answer : Enzymes

Biochemically the ribosome consists of _______________ and some 50 structural . (A) mRNA, Carbohydrates (B) tRNA, lipids (C) mRNA, Proteins (D) rRNA, Proteins

Description : Biochemically the ribosome consists of _______________ and some 50 structural . (A) mRNA, Carbohydrates (B) tRNA, lipids (C) mRNA, Proteins (D) rRNA, Proteins

Last Answer : (D) rRNA, Proteins

What is the name of the physical process that finally splits the parent cell into two identical daughter cells?

Description : What is the name of the physical process that finally splits the parent cell into two identical daughter cells?

Last Answer : Cytokinesis. Also more commonly known as cell division

During mitosis, the eukaryotic cell nucleus splits in two, followed by division of the parent cell into two daughter cells. Mitosis progresses through five separate morphologically distinct phases. Name, in order, these five phases of mitosis.

Description : During mitosis, the eukaryotic cell nucleus splits in two, followed by division of the parent cell into two daughter cells. Mitosis progresses through five separate morphologically distinct phases. Name, in order, these five phases of mitosis.

Last Answer : Prophase, prometaphase, metaphase, anaphase, and telophase.

Which cell organelles are well-developed in secretory cells ?

Description : Which cell organelles are well-developed in secretory cells ?

Last Answer : In secretory cells, like the secretory cells of endocrine glands, organelles related to production, processing and exportation of substances are widely present and well-developed. These ... protein synthesis between the cytoplasm and the nucleus. Rough endoplasmic reticulum Golgi apparatus

Which are the cell organelles that participate in the cell division and in the formation of cillia and flagella of some eukaryotic cells ?

Description : Which are the cell organelles that participate in the cell division and in the formation of cillia and flagella of some eukaryotic cells ?

Last Answer : The organelles that participate in the cell division and in the formation of cilia and flagella of some eukaryotic cells are the centrioles. Some cells have cillia (paramecium, the bronchial ciliated ... are very important for cell division. Cell Structure Review - Image Diversity: centrioles