How does a ribosome produce protein in a Cell?
Ribosomes start protein synthesis in the cytoplasm. Synthesis is completed either in the cytoplasm or in the lumen of the rough endoplasmic reticulum.
All proteins begin as polypeptides (chains of amino acids). The synthesis of a chain starts when a free (unattached) ribosome begins to move along a molecule of messenger RNA (mRNA) in the cytoplasm.
Once a small number of amino acids have been incorporated into the chain, large molecules in the cell "inspect" the chain. Certain sequences of amino acids are recognized as marking the chain for synthesis in the lumen of the rough endoplasmic reticulum (ER).
If the chain has one of these sequences, the mRNA and ribosome are moved to the ER and the ribosome is fixed in the ER membrane in such a way that the mRNA remains in the cytoplasm but the polypeptide chain is in the lumen of the ER. It is in the lumen that the chain is completed, and subsequently coils and folds to form the finished polypeptide.
If, on the other hand, the chain does not have one of these marker sequences, synthesis of the chain and its subsequent coiling and folding all take place in the cytoplasm.
Which theory tries to explain the origin of endoplasmic reticulum nuclear membrane?
The theory of endosymbiosis which believes that nuclear membranes and organelles such as the mitochondrian have evolved from a semi"mutation" in which a prokaryotic cell was engulfed by a eukaryotic cell and instead of being digested it survived and has evolved into key features of the eukaryotic cell. Evidence for this is the fact that the mitochondrian have their own ribosomes ( of which are the prokaryotic variety) and their own DNA which allow them to make their own proteins that can be used in synthesis of adenosine triphosphate (ATP)
Two different specialized Cell types?
There are two hundred and twenty 'different specialized Cell types'.
So pick two - muscle and nerve tissues; bone and vascular [blood circulating] tissues; skin (integument) and stomach / intestine; etcetera.
What makes the water molecule polar?
a water molecule is polar because their is an uneven distributive of electrons between the oxygen and hydrogen atoms. the negative pole is near the oxygen atom and the positive pole is between the hydrogen atoms.
What organisms perform nitrogen fixation?
There is a bacterium that resides within the rhizomes - nodules found within the roots - of Legumes that transforms atmospheric N2 [gaseous molecular Nitrogen] into its forms [NO2 and NO3] that are biochemically active.
Where does oxygen come from in oxidative phosphorylation?
Oxygen in oxidative phosphorylation comes from the air we breathe. During the electron transport chain, oxygen acts as the final electron acceptor, combining with protons to form water. This reaction is essential for the generation of ATP, the energy currency of the cell.
Three substages of interphase?
What is the Cell produced when a male gamete fuses with a female gamete?
Scientifically speaking, the product is a zygote. A zygote is the term for a fertilized egg in its early stages of development and when it has not yet arrived at the uterus(the egg is fertilized at the fallopian tubes). When it has attached itself to the uterus, it is called a blastocyte. After 7 to 10 days after the fertilization, it is called a gastrula. When the stem cells have fully specialized, it is called a embryo.
How many base pairs are present in this segment of DNA Model?
To determine the number of base pairs in a segment of DNA, you would need to know the length of the segment in base pairs. Each base pair consists of two nucleotides bonded together, such as adenine-thymine or cytosine-guanine. You can count the bases in the segment and divide by two to get the number of base pairs.
Does the Calvin cycle require RuBP?
Yes, the Calvin cycle requires RuBP (ribulose-1,5-bisphosphate) as it is the starting molecule for carbon fixation. RuBP reacts with CO2 to form an unstable intermediate that eventually leads to the synthesis of sugars such as glucose.
Hydrolysis is a chemical reaction in which a water molecule is used to break down a larger molecule into smaller units. It is involved in processes such as digestion, breaking down complex carbohydrates, fats, and proteins into simpler forms that the body can absorb and use for energy. Additionally, hydrolysis plays a role in metabolic reactions, breaking down molecules to release stored energy.
What class of nutrient produces certain hormones and forms a coating on nerves?
Lipids, specifically phospholipids, are the class of nutrient that can produce certain hormones and form a coating on nerves. These essential fats play a crucial role in cellular structure and signaling, including hormone production and nerve insulation.
Can living things survive with out enzymes?
Living things rely on enzymes to carry out essential chemical reactions in their bodies. Without enzymes, these reactions would occur too slowly or not at all, leading to the inability to survive. Therefore, living things cannot survive without enzymes.
What happens during aerobic respiration?
it takes place in animals all the time. When we breathe in we take on oxygen which combines with gluscose in aerobic respiration to produce energy.
oxygen+glucose---- carbon dioxide+ water+ energy
Hypoxanthine is a naturally occurring purine derivative. It is occasionally found as a constituent of nucleic acids, where it is present in the anticodon of tRNA in the form of its nucleoside inosine. It has a tautomer known as 6-hydroxypurine. Hypoxanthine is a necessary additive in certain cell, bacteria, and parasite cultures as a substrate and nitrogen source. Hypoxanthine is also a spontaneous deamination product of adenine. Because of its resemblance to guanine, the spontaneous deamination of adenine can lead to an error in DNA transcription/replication.
What nitrogenous bases are pyrimidines?
Pyrimidines are the single ringed structures-Cytosine and Thymine
Purines are the double ringed structures- Adenine and Guanine.
What is the reaction mechanism of orcinol in the estimation of RNA?
Furfural cannot be formed from ribosides until the glycosidic
linkage has been split; the purine-ribose links of RNA are easily
hydrolysed by hot acid, while the pyrimidine-ribose links are much more
resistant, and the orcinol method is commonly supposed to determine only
the purine-bound ribose of RNA.
What is a mixture that is the same homogenous?
A homogenous mixture is a combination where the components are evenly distributed throughout, resulting in a uniform composition. An example of a homogenous mixture is a solution of salt dissolved in water.
What happens to DNA during the S stage of interphase?
During the S stage of interphase, DNA undergoes replication, where the DNA molecules are duplicated. This results in each chromosome consisting of two identical sister chromatids attached at a region called the centromere. This ensures that each daughter cell after cell division receives a complete copy of the genetic material.
What do proteins do when energy is released from the ATP?
To access the energy stored in ATP, proteins bind ATP and uncouple the phosphate group. The ADP that is formed is released, and the protein binding site can once again bind ATP.
-Got this from my biology book; page 223; bottom caption
A chemical reaction that requires a net input of energy?
An example of a chemical reaction that requires a net input of energy is photosynthesis. In this process, plants use energy from sunlight to convert carbon dioxide and water into glucose and oxygen. The energy from sunlight is required to drive this reaction and is absorbed by chlorophyll in plant cells.
Formation of Myelin Sheath and also Neuron introduction?
The formation of myelin sheath around the axon is called the myelinogenesis. In the peripheral nerve, the myelinogenesis starts at 4th month of intrauterine life. It is completed only in the second year after birth. Before myelinogeneis, Schwann cells of the neurilemma are very close to axolemma as in the case of unmyelinated nerve fiber. The membrane of the schwann cell is double layered. The schwann cells wrap up and rotate around the axis cylinder in many concentric layers. The concentric layers fuse to produce the myelin sheath but the cytoplasm of the cells is not deposited. Outermost membrane of Schwann cell remains as neurilemma. Nucleus of these cells remains in between myelin sheath and neurilemma. In the central nervous system, the schwann cells are absent and the myelin sheath is formed by the neuroglial cells called the oligodendroglia.
What oligonucleotide probe would best hybridize with the DNA sequence 5'-AAAAGGTTCC-3'?
3' TTTTCCAAGG 5' for a DNA probe; 3' UUUUCCAAGG 5'for an RNA probe.
The reasons:
1
Paired nucleic acid strands are antiparallel, meaning that they run in opposite directions. So the 5' end of one strand is opposite the 3' end of the other strand.
2
Hybridizing follows base pairing rules: A pairs with T (in DNA) or U (in RNA), and C pairs with G.
Why is it necessary for a biologist to have expertise in the field of chemistry?
Biologists study chemistry because it is the basis of a living things. For example aerobic respiration (us breathing) is breathing in Oxygen (O2) and breathing out Carbon Dioxide (CO2) these are elements in the Periodic Table which is a part of chemistry.