Cell Biology Lab final
explain differences between es and ips cells, what are some potential uses of these pluripotent cells in medical technology
The difference between iPS cells and ES cells The same genes that are chemically altered during normal cell differentiation, as well as when normal cells become cancer cells, are also changed in stem cells that scientists derive from adult cells, according to new research from Johns Hopkins and Harvard.
is the theory of endosymbiosis konwn fact, understand the similarities between mitochondria chloroplasts and bacteria support this theory, they do not prove it
The endosymbiosis theory is just a theory, not fact. Just as the question states, there is supporting evidence, but it is not definitive.
what are the ethical concerns with es cloning techniques
The ethical issues with reproductive cloning include genetic damage to the clone, health risks to the mother, very low success rate meaning loss of large numbers of embryos and fetuses, psychological harm to the clone, complex altered familial relationships, and commodification of human life.
how is that teeny squishy fragile cells are able to form gigantic organisms like redwood trees elephants, what provides the support
The extracellular matrix. The support outside of the cells gives them the ability to grow enormous like the blue whale or the red wood.
what is the difference between reproductive and therapeutic cloning using es cells
• Therapeutic cloning does not produce a whole new copy of an organism but a copy of a part of an organism mainly an organ or tissue. But reproductive cloning produces a whole new copy of an organism. • Therapeutic cloning is used for medical treatment purposes, and reproductive cloning is used for reproductive purposes.
what is collagen and how common is it, how or where is collagen assembly carried out
i. Collagen is the main support protein in the em in various tissues. It makes up around 25% of animal whole body protein by mass. Assembly is found mostly in the fibrous tissues of the body such as tendons.
what are gags and proteoglycans, are they hydrophilic or hydrophobic, where are they found in the body
i. Gags are polysaccharide chains that are linked to core proteins to form proteoglycans. Proteoglycans are heavily glycosylated. The basic component is a GAG chains. They are extremely hydrophilic. They are found in the connective tissues of the body.
articular cartilages are made of what, where are they found and what is their function
i. They are made of collagen and they are found in the joints of the body. The function of them is to provide support and decreases friction.
what three things happen during g1 phase
The cell grows (organelles replicate, cell volume doubles), the cell does what a cell normally does (normal metabolic processes), and there is a G1 checkpoint (asks if the cell is big enough and if the environment is suitable).
what is the total atp yield from oxidation of glucose, how much of this is from op, what is % efficiency of op
The complete oxidation of glucose yields 36 ATP, about 34 of those are from oxidative phosphorylation (because on 2 net ATP are produced during glycolysis.
what is ehlers danos syndrome, mutations in which genes can cause it
i. This is a disorder that is messing with the function of connective tissues. For instance, someone can have super stretchy skin because of it. Joints can dislocate much easier.
name 5 types of cell junctions in animals, what are the key features of each, which are most similar to each other
i. Tight- they are made up of sealing strands that hold plasma membranes together. They are mostly formed from a group of proteins called claudins they are found in epithelia. ii. Hemidesmosomes- a structure of half a desmosome they are found on the basal surface of some epithelial cells. iii. Gap junctions- they are found in nerves can also be called the electrical synapse. iv. Desmosomes- a site of adhesion between epithelial cells consisting in each cell of a dense attachment plaque with associated intermediate filaments and transmembrane proteins known on cadherins. v. Adherens junction- a component just beneath the zonula occludens. The extracellular space at which adherens junctions is spanned by the extracellular aspects of cadherins molecules. They are found between epithelial cells. vi. Some that are like each other hemidesmosomes and desmosomes. They are anchoring into cells such as the basal lamina.
how are differences between the tissues of animals plants reflective of their different life history strategies
plants are sitting there and they die when a predator shows up. they have different defense mechanisms to help fight them off. Animals will usually run away from predators.
what 4 things can intracellular signaling pathways do with signal pages 534 and 535 figure 16.13
relay transduce and amplify integrate distribute
who first observed and recorded cell walls, what centruy was this
robert hooke in the 17th century
matrix cristae intermembrane space
specialized structures are embedded within this tissue folds in the inner membrane of mitochondria in between the cristae and the matrix
what is the difference between primary and secondary cell walls, which is more rigid, which allows for cell growth
the secondary cell wall is a structure found in many plants, located between the primary cell wall and the plasma membrane. The secondary cell wall allows for growth. The secondary wall is more rigid.
have humans been clones yet, explain answer
yes they have been cloned however usually the embryo is destroyed because we have yet to figure out what will happen if a full human is cloned
antenna complex reaction center calvin cycle rubisco glyceraldehyde 3- phosphate
Antenna complex = light-harvesting complex inside thylakoid membrane Reaction center = a complex made up of several proteins, pigments, etc. that assist with energy conservation reactions in photosynthesis Calvin cycle = chemical reactions within chloroplasts during photosynthesis; light-independent and takes place after light energy has been captured from the sun Rubisco = enzyme in chloroplasts involved in carbon fixation Glyceraldehyde-3-phosphate = product of Calvin cycle; some used to regenerate RuBP to continue cycle
how does p53 arrest cell replication, when is it activated
P53 levels are low in a normal cells, but they can rise when a cell is under stress. This will trigger growth arrest, DNA repair mechanisms, and/or cell death.
What causes androgen insensitivity syndrome?
A congenital lack or malfunction of the androgen receptor. doesn't allow testosterone
explain the role of stem cells and cell differentiation in tissue renewal in the three examples we looked at in lecture: intestinal villi, skin, and blood cells
Stem cells are undifferentiated cells that really have no function and can become any cell they want to. Differentiated tissues have a specific function for what ever genes are expressed be it a heart or liver cell.
explain the relationship between the antenna complexes and reaction center, which absorbs light, where is an electron kicked out see 14.7 moodle movie
Antenna complexes harvest and absorb light while the reaction center chemically captures energy via chemical bonds, so the antenna complexes hand off light/energy to the reaction center. An electron is kicked out from the reaction center and transferred to an electron acceptor. See image:
besides driving atp synthase, what else does the h+ gradient do in mitochondria
Besides its function in ATP synthase, it also maintains the pH in the matrix versus the inner membrane (pH of 7.8 versus 7.4 respectively)
what is the role of Cdks in the cell cycle, when are m-cdks active and s cdks
CDKs are cyclin-dependent kinases, which regulate the cell cycle and tell the cell that it is ready to move on to the next stage of the cell cycle. M-Cdks are active during M phase. S-Cdks are active during S-phase.
what doe cdc25 do to initiate m phase, why is this an example of a + feedback loop
Cdc25 is a dual-specificity phosphatase first isolated from the yeast Schizosaccharomyces pombe as a cell cycle defective mutant. As with other cell cycle proteins such as Cdc2 and Cdc4, the "cdc" in its name refers to "cell division cycle". Dual-specificity phosphatases are considered a sub-class of protein tyrosine phosphatases.
describe the relationship between cdks and their cyclins
Cdks are dependent on cyclins, which are regulatory proteins. Cyclins will bind to Cdks and activate them to go ahead and phosphorylate other neighboring molecules.
what does cell theory state
Cell theory states that all living organisms are composed of one or more cells, the cell is the basic unit in living organisms, and all cells come from pre- existing cells.
what class of signal molecules are able to directly cross the cell membrane to internal receptors, what are some examples of these signal molecules
Cell to cell recognition could be an example of this type of signaling, and some examples would include membrane bound cell surface molecules, glycoproteins, and glycolipids. The would be used to guard against unfamiliar cells and invaders and are part of the immune response. • What causes Androgen Insensitivity Syndrome?
generally speaking do cells tend to spend more time in g1 s g2 or m phase
Cells spend most of their time in the G1 phase, otherwise known as interphase. This is a time for cell growth.
how or where are cellulose microfibrils produced, how is orientation controlled, why is a plant cell wall like kevlar body armor
Cellulose microfibrils are produced at the plasma membrane by the cellulose synthase complex, which is proposed to be made of a hexameric rosette that contains three cellulose synthase catalytic subunits for each of the six units. Cell wall is a tough and rigid layer around the cell of certain organisms like plants and bacteria, which provides structural support and protects the cells. It is not necessary for animal cells to have a cell wall due to a various reasons like,
chemiosmosis OP ATP synthase electron transport chain
Chemiosmosis = movement of ions across membrane, down gradient Oxidative phosphorylation = process in which ATP is formed via series of electron transfers ATP synthase = enzyme that creates ATP Electron transport chain = series of complexes that facilitate transfer of electrons via donors or acceptors
chloroplast chlorophyll thylakoids grana stroma
Chloroplast = plastid containing the pigment chlorophyll/where photosynthesis happens Chlorophyll = green pigment of plants Thylakoids = flattened sacs inside chloroplasts/where light reactions take place Grana = membranous structure inside chloroplasts that contains chlorophyll and also where light reactions occur Stroma = clear fluid surrounding grana w/in chloroplasts
what are three enzyme complexes that make up the electron transport chain in mitochondria, what does each do
Complex I = accepts electrons from NADH, dissociating to NAD+ and H+; contains FMN; also known as NADH reductase Complex III = accepts FAD; also known as cytochrome reductase Complex IV = accepts 2H+ and ½ O2; cytochrome c used O2
explain how different combinations of receptors and intracellular signaling molecules can result in different cells having very different responses to the same esm figure 16.5
Different combinations of signaling and receptors can lead to a diverse among of cellular responses for many reasons. One reason could include that induction or inhibition of transcription of certain genes and/or the activity levels of certain enzymes. This can have a variety of effects on the cell and subtle changes can have a huge difference physiologically.
what are epithelial sheets and what are their functions
Epithelial cells are one example of a polarized cell type, featuring distinct 'apical', 'lateral' and 'basal' plasma membrane domains. Epithelial cells connect to one another via their lateral membranes to form epithelial sheets that line cavities and surfaces throughout the animal body.
explain how fibroblasts navigate around connective tissues
Fibroblast. A fibroblast is a type of biological cell that synthesizes the extracellular matrix and collagen, produces the structural framework ( stroma) for animal tissues, and plays a critical role in wound healing. Fibroblasts are the most common cells of connective tissue in animals. Basically they are crawling around the matrix allowing for fluid movement
what are the cell junctions between plants called, how do they differ from the gap junctions found between animal cells
Gap Junctions. Gap junctions in animal cells are like plasmodesmata in plant cells in that they are channels between adjacent cells that allow for the transport of ions, nutrients, and other substances that enable cells to communicate (Figure 5). Structurally, however, gap junctions and plasmodesmata differ. Figure 5. Cells can also communicate with each other via direct contact, referred to as intercellular junctions. There are some differences in the ways that plant and animal cells do this. Plasmodesmata are junctions between plant cells, whereas animal cell contacts include tight junctions, gap junctions, and desmosomes.
how does dopamine influence the gap junctions in retinal neurons
Gap junctions in retinal photoreceptors suppress voltage noise and facilitate input of rod signals into the cone pathway during mesopic vision. These synapses are highly plastic and regulated by light and circadian clocks.
what happens when a cell receives no ESMs
I believe that an ESM refers to Endothelial Cell-specific Molecules, and I would assume that if a cell does not receive an ESM then it is not capable of responding in any way. So no signal = no response. This could lead to malfunction of that cell and apoptosis. Not sure if ESM is referring to something different in your class, however.
what happens in g2, mitosis, and cytokinesis
In G2 phase, the cell will grow; keep in mind this is in between the DNA synthesis phase and mitosis. Mitosis is when the cell actually, physically divides into two daughter cells. Cytokinesis is when the cytoplasm finally divides at the end of mitosis, so now you ACTUALLY have two cells with two different membranes.
in a nutshell how are photosynthesis and oxidative phosphorylation similar to each other how are they different
In a nutshell, in oxidative phosphorylation, the energy will come from the electrons that are produced by oxidation of biological molecules. In photosynthesis, however, the energy will come from light from the sun.
orc cdc6 s cdk cdc25 and m cdk
In molecular biology, origin recognition complex (ORC) is a multi-subunit DNA binding complex (6 subunits) that binds in all eukaryotes in an ATP-dependent manner to origins of replication. ... ORC directs DNA replication throughout the genome and is required for its initiation. Cdc6, or cell division cycle 6, is a protein in eukaryotic cells that is studied in the budding yeast Saccharomyces cerevisiae. It is an essential regulator of DNA replication and plays important roles in the activation and maintenance of the checkpoint mechanisms in the cell cycle that coordinate S phase and mitosis. Cdc25 is a dual-specificity phosphatase first isolated from the yeast Schizosaccharomyces pombe as a cell cycle defective mutant. As with other cell cycle proteins or genes such as Cdc2 and Cdc4, the "cdc" in its name refers to "cell division cycle".
summarize why cell signaling is important to both unicellular and multicellular organisms see intro to chapter 16 page 525
In multicellular organisms, signaling is important for coordinating different cellular activities, like developing a zygote into a fully formed organism. In unicellular organisms, signaling is important because it aids in finding different mating types in order to facilitate sexual reproduction.
how does cytokinesis differ between plants and animals
In plants, the cell plate forms along equator of P cell (parent cell) and then new cell wall and plasma membrane form along each side of cell plate. In animals, the cell pulls apart and then splits in middle, essentially.
how are ips cells induced
Induced Pluripotent Stem Cells (iPS) iPSC are derived from skin or blood cells that have been reprogrammed back into an embryonic-like pluripotent state that enables the development of an unlimited source of any type of human cell needed for therapeutic purposes.
what are the inputs and products of the calvin cycle, what role does rubisco play
Inputs of the Calvin cycle are CO2, ATP, and NADPH. Outputs of the Calvin cycle are sugar, ADP, NADP+, and inorganic phosphate. Rubisco catalyzes the first step of carbon fixation in the Calvin cycle, which is the process of converting CO2 into organic compounds for living organisms (like for sugar).
what role do mitogens play in the cell cycle, specifically the g1 to s transition
It is important for determining whether a cell is ready to replicate successfully. The other option the cell has here is to remain in interphase for a longer period of time or indefinitely.
m g1 s g2 phases interphase mitosis cytokinesis
M phase. During the mitotic (M) phase, the cell divides its copied DNA and cytoplasm to make two new cells. M phase involves two distinct division-related processes: mitosis and cytokinesis. ... You can learn more about these stages in the video on mitosis. G1 phase. G1 is an intermediate phase occupying the time between the end of cell division in mitosis and the beginning of DNA replication during S phase. ... S phase, or synthesis, is the phase of the cell cycle when DNA packaged into chromosomes is replicated. S phase (Synthesis Phase) is the phase of the cell cycle in which DNA is replicated, occurring between G1 phase and G2 phase. Since accurate duplication of the genome is critical to successful cell division, the processes that occur during S-phase are tightly regulated and widely conserved.
how are m-cdks switched off and on fig 18.5 page 612
M-Cdks are inactivated by Hct1 and Sic1. They are activated by cyclin binding.
what is merrf, and how does it show us that oxidative phosphorylation is important
MERRF means myoclonic epilepsy with ragged-red fibers, which is a muscular and nervous system disorder. It is also considered a disorder of oxidative phosphorylation inherited on the maternal side that results in too much calcium build up in the cell and increased production of ROS, or reactive oxygen species.
what features do mitochondria and chloroplasts share with free living bacteria
Mitochondria and chloroplasts each have separate DNA, they each use that DNA to produce proteins required specifically for their function, they both have a double plasma membrane, which are all shared features with free living bacteria. They also all replicate in a similar way, directing their own division.
what are some cool properties of mitochondria 451 and 452
Mitochondria have their own genome and DNA, mitochondrial DNA is circular, they are present in almost all body cells besides red blood cells, and they float freely in the cytoplasm.
what is the role of rb protein in restricting cell replicaitons
Mitogens induce cell division, so they trigger mitosis. Therefore they are crucial in the cell getting pushed along from G1 phase to S phase all the way down the line to M phase.
what are the functions of the cytoskeletal structures presenting during m phase
Mitotic spindles will attach to the kinetochores (centers) of chromosomes to pull them apart during M-phase into their respective daughter cells.
how much energy in glucose is released during glycolysis
More energy is gained from glycolysis than energy used. There is a gross ATP value of 4 and a net ATP value of 2, meaning that you get 2 ATP as the grand total from glycolysis.
what effect does nitric oxide have on smooth muscle, how is it produced
Nitric oxide will relax smooth muscle cells by increasing cGMP (cyclic guanosine monophosphate). Nitric oxide is produced by L-arginine (an amino acid) by the body with help from the enzyme nitric oxide synthase. It is mainly synthesized in the innermost layer of the blood vessels (endothelium) but it can be produced in other cells as well.
do most cells possess a single type of receptor, or many types of receptors, in other words, is cell behavior usually regulated by one signal or combinations of signals
No, most cells possess multiple types of receptors and cell behavior is heavily reliant on a COMBINATION of different signals for regulation.
what are the main things that happen during photosystem 2 and 1
Photosystem II comes before Photosystem I. In PSII, light is absorbed by pigments, energy is passed inwards until it reaches the reaction center, energy is transferred to P680 and an electron gains energy, then that electron is passed to an electron acceptor and replaced with an electron from H2O. In PSI, an electron joins P700 chlorophylls (a special pair) in the reaction center, light energy gets absorbed by the pigments, also gets passed in until it reaches the reaction center, the P700 electron gains energy and is transferred to an electron acceptor, the special pair's electron which is now missing gets replaced by a new electron from PSII via electron transport chain.
why are plants green
Plants are green because they contain a pigment called chlorophyll that does not absorb the wavelength of green light and therefore reflects green light to human eyes.
so plants have both chloroplasts and mitochondria. instead of making sugars, why don't they just use the atp produced in photosynthesis for their metabolic needs page 478
Plants need materials to grow, not just energy, and glucose is an important "building block" for life. Additionally, the sun goes away at night and during certain seasons, and the plant can't really store ATP. It can, however, store glucose.
name the 5 stages of mitosis in order, what key events happen during each stage
Prophase = chromosomes condense and there is no nuclear envelope, Metaphase = chromosomes line up at metaphase plate in center of cell, Anaphase = chromatids are pulled part to separate side of the elongated cell, Telophase = cell is pulling a part more based on the two poles, Cytokinesis = full division of the two daughter cells
signaling transduction signaling cell target cell receptors extracellular and intracellular signaling molecules effector proteins
Signal transduction (also known as cell signaling) is the transmission of molecular signals from a cell's exterior to its interior. Signals received by cells must be transmitted effectively into the cell to ensure an appropriate response. This step is initiated by cell-surface receptors. a cell which bears receptors for a hormone, drug, or other signaling molecule, or is the focus of contact by a virus, phagocyte, nerve fiber, etc. Signaling molecules interact with a target cell as a ligand to cell surface receptors, and/or by entering into the cell through its membrane or endocytosis for intracrine signaling. In biochemistry, an effector molecule is usually a small molecule that selectively binds to a protein and regulates its biological activity. In this manner, effector molecules act as ligands that can increase or decrease enzyme activity, gene expression, or cell signaling.
explain the concept of signal transduction
Signal transduction IS cell signaling, but more specifically it is the transmission of different molecular signals from the outside of a cell to the inside of a cell.
describe the rpocess of somatic cell transfer to create clones from adult cells
Somatic cell nuclear transfer. In genetics and developmental biology, somatic cell nuclear transfer (SCNT) is a laboratory technique for creating an ovum with a donor nucleus. It can be used in embryonic stem cell research, or in regenerative medicine where it is sometimes referred to as "therapeutic cloning.".
explain why some cell responses are faster than others figure 16.7
Some cell responses may be faster than others because the signal results in a direct response while some require secondary messengers and other co- signaling molecules. Additionally, if an ion is involved (voltage gated ion channels, ligand gated channels, etc.) then the amount of that ion/ligand available might affect the efficiency and speed with which a cell can respond.
when palnts produce an excess of g3p, how can they store energy
Some of the G3P molecules are directly used in making glucose and other G3P molecules are recycled and will regenerate a RuBP acceptor
steroid hormons (cortisol and testosterone nuclear receptors nitric oxide
Steroid hormone, any of a group of hormones that belong to the class of chemical compounds known as steroids; they are secreted by three "steroid glands"—the adrenal cortex, testes, and ovaries—and during pregnancy by the placenta. All steroid hormones are derived from cholesterol. In the field of molecular biology, nuclear receptors are a class of proteins found within cells that are responsible for sensing steroid and thyroid hormones and certain other molecules.
g0 rest phase terminal differentiation mitogens rb protein retinoblastoma p53
The G0 phase or resting phase is a period in the cell cycle in which cells exist in a quiescent state. G0 phase is viewed as either an extended G1 phase, where the cell is neither dividing nor preparing to divide, or a distinct quiescent stage that occurs outside of the cell cycle. Terminal Differentiation Markers. ... The terminally differentiated cell, which has a specific function within the organism, will proliferate as only one cell type. These cells express genes that are specific to their cell type and function. Mitogenesis is the induction (triggering) of mitosis, typically via a mitogen. The mechanism of action of a mitogen is that it triggers signal transduction pathways involving mitogen-activated protein kinase (MAPK), leading to mitosis. p53, also known as TP53 or tumor protein (EC :2.7.1.37) is a gene that codes for a protein that regulates the cell cycle and hence functions as a tumor suppression. It is very important for cells in multicellular organisms to suppress cancer.
in op energized electrongs from nadh are use to do what, what is the final electron acceptor, stop and think... this is the sole reason why you need to breathe oxygen, and why you will die if you stop breathing
The final electron acceptor is oxygen, which is why we breathe in oxygen. All our cellular processes will cease if we do not have sufficient oxygen. The energized electrons from NADH are used in the electron transport chain are reduced to water.
what are five types of cell signaling, be able to explain the important features that distinguis each and be able to provide an example for each
The five different cell signaling pathways are (1) contact dependent, (2) autocrine, (3) paracrine, (4) synaptic, and (5) endocrine. Contact dependent signaling is a type of cell/cell or cell/matrix signaling that is found in multicellular organisms and is only accomplished with close contact; an example would be cytokine and chemokine signaling in the immune response. Autocrine signaling occurs when a cell secretes a chemical messenger, like a hormone, that binds to autocrine receptors on the same cell and results in changes to the cell; an example would be cytokine interleukin-1 in monocytes (immune system). Paracrine signaling is cell to cell signaling where one cell produces a signal to induce a change in nearby cells; an example is growth factors or clotting factors. Synaptic signaling occurs between cells with a synapse, like between a neuron and a muscle. Finally, endocrine signaling is when endocrine cells release hormones that act on a distant target, like ADH retaining water within the kidney cells.
Be familiar with the energy carrier molecules discussed in chapter 14 adp gdp nad+ fad and nadp+ (atp, gtp, nadh, fadh2, nadph
The function of the energy carrier molecules are to temporarily store energy during metabolic processes like photosynthesis, aerobic respiration, etc. ADP is a low-energy form of ATP, GDP is a low-energy form of GTP, NAD+ is a low- energy FORM OF NADH, FAD is a low-energy form of FADH2, and NADP+ is a low-energy form of NADPH. ADP/ATP and GDP/GTP are inputs and outputs of metabolic processes, while NAD+/NADH, FAD/FADH2, and NADP+/NADPH are used to transfer electrons during metabolic processes.
which side of the thylakoid membranes has high concentration of H+
The internal side of the thylakoid membrane has a higher concentration of H+ (so the inside)
what are the goals of s phase
The main goal of S phase is to successfully replicate genetic material.
mitotic spindle contractile ring centrosome centriole kinetochores
The mitotic spindle is the macromolecular machine that segregates chromosomes to two daughter cells during mitosis. The major structural elements of the spindle are microtubule polymers, whose intrinsic polarity and dynamic properties are critical for bipolar spindle organization and function. ormed during cytokinesis, the last step of cell division, the contractile ring is composed of filamentous actin (F-actin) and the motor protein myosin-2, along with additional structural and regulatory proteins. an organelle near the nucleus of a cell which contains the centrioles (in animal cells) and from which the spindle fibers develop in cell division. a minute cylindrical organelle near the nucleus in animal cells, occurring in pairs and involved in the development of spindle fibers in cell division. a complex of proteins associated with the centromere of a chromosome during cell division, to which the microtubules of the spindle attach.
what are the main goals of the cell cycle page 604 the most basic function
The most basic function of the cell cycle is to replicate DNA and create two resulting daughter cells.
where does the special pair get a replacement electron from, for every molecules of o2 produced how many h+ are produced, energized electrons
The special pair gets a new electron from PSII (photosystem II), which comes in via the electron transport chain
explain two main parts that make up chemiosmosis, how important is it to life on earth
The two main parts are the difference in charge (electrical) and the difference in concentration (chemical). Chemiosmosis is critical to life on earth, as it is how ATP is produced.
what are the two steps to photosynthesis, what happens at each, where in the chloroplasts do they occur
The two steps of photosynthesis are the (1) light-dependent reactions and (2) the Calvin cycle, which are light-independent reactions. In light-dependent reactions, energy from light (via the sun) is absorbed by chlorophyll within the plant cell and is converted in chemical energy which is manifested in the form of ATP, NADPH, and other electron carrier molecules. In the Calvin cycle (cytoplasm), sugar molecules are made from CO2 using the chemical energy that was harvested during the previous set of reactions.
explain the role of the cell cycle control system. where are three main checkpoins located, and what questions does the cell cycle control system ask at these checkpoints
There are 3 main checkpoints in the cell cycle, which are the G1 checkpoint, the G2 checkpoint, and the M checkpoint. The G1 checkpoint is when the cell decides whether or not it will divide; it asks is the cell large enough to divide? Does it have enough nutrients? Is it receiving signals? Is the DNA damaged?. The G2 checkpoint asks is any of the DNA damaged? Was the DNA completely and totally copied during S (synthesis) phase? Finally, the M checkpoint checks for chromosome attachment to the spindle of the metaphase plate during replication. All these control points are designed to prevent abnormal cell growth which can lead to things like cancer.
why is it important that m cdks are inactivated at the start of g1 phase
This could potentially lead to excess cell division, because the M-Cdks are a signal to the cell that it is time to undergo mitosis. However, in the G1 phase, it is a time for the cell to grow and metabolize nutrients, not to divide. This could potentially lead to larger issues like uncontrolled cell division/tumor growth down the line.
kinases phosphatases cyclin dependent kinases cdk inhibitor proteins
an enzyme catalyzes the transfer of a phosphate group from atp to specified molecule A kinase is an enzyme that attaches a phosphate group to a protein. A phosphatase is an enzyme that removes a phosphate group from a protein. Together, these two families of enzymes act to modulate the activities of the proteins in a cell, often in response to external stimuli. Through phosphorylation, Cdks signal the cell that it is ready to pass into the next stage of the cell cycle. As their name suggests, Cyclin-Dependent Protein Kinases are dependent on cyclins, another class of regulatory proteins. Cyclins bind to Cdks, activating the Cdks to phosphorylate other molecules.
what is cancer, is a single mutation sufficient to cause cancer, why does cancer become more common in older oragnisms
cancer is the a disease caused by an uncontrolled division of abnormal cells in a part of the body. Cancer is a group of diseases caused by a series of mutations involving abnormal cell growth with the potential to invade or spread to other parts of the body. Each mutation alters the behavior of the cell somewhat. There are over hundred different known cancers that affect humans. So, cancer is not a single disease. The reason they are happening in older people is because they are at the ends of their genes. The DNA is starting to wilt away and isn't as healthy, so that leaves room for cancer.
what are the three things cells do to keep tissue renewal organized pages 704 and 705
cell communication selective cell adhesion cell memory
plant tissues are stregnthened primarily by what extracellular matrix
cell wall which is primarily made up of cellulose and pectin molecules
the tissues of multicellular organisms are composed of what
cells and extra cellular matrix
why is the g1 checkpoint so imprtant, what options does a cell have here
cells can go into g0/ rest phase which they can be used later in the cell cycle. The idea is that it is so important because this is where the cell cycle really starts, and if a cell is bad this checkpoint can be used to get rid of that bad cell.
what macromolecule provides the tensile strength for cell walls, these macromolecules are organized into fibers called what
cellulose which is a sugar most abundant on earth. they are organized into fibers called lignin.
what are the 4 animal tissue types, connective tissues are composed of what
connective- largely composed of extracellular matrix, collagen, cells ahve things like osteblasts and fibroblasts. epithelial muscle nervous
what range of times do actively dividing cells take to complete a cell cycle 18.1
depending on the cell it can take hours sometimes a day
describe how both gain of function and loss of function mutations can cause a cell to become cancerous. which of these two is dominant, recessive
gain of functions is dominant. loss of function is recessive. Gaining too much function can allow for a cell to over replicate causing cancer. Losing function in genes such as oncosuppressors can cause tumors to begin to spread to other parts of the body.
