Some white blood cells are more prolific than others. Neutrophils are the most prolific and comprise about 50% of the white blood cell volume. Lymphocytes are about 20% of the blood volume.
Enzymes are made of proteins, and often end with the suffix “ase”.
A restriction endonuclease (also known as a restriction enzyme) is a protein produced by bacteria that cleaves DNA at specific sites.
A ligase is an enzyme that catalyzes the joining of two large molecules by forming a new chemical bond.
Haemoglobin, rubisco are quaternary protein structures.
The primary level of protein arrangement is the amino acid sequence making each polypeptide. The secondary level of arrangement is the coiling and twisting of amino acids that give a more stable arrangement. The tertiary level of arrangement is the 3D shape of a single polypeptide. The quaternary level of arrangement involves the interaction between more than one polypeptides making a functional protein.
DNA does not contain a ribose sugar like the other types of RNA, instead it has a deoxyribose.
The genetic code is universal because it contains ATGC no matter the organism.
Mitochondria are the location of cellular respiration (the process that is responsible for creating ATP).
The Golgi body is responsible for storing, modifying and the final packaging of proteins in preparation for their export from the cell.
RNA processing occurs in the nucleus during transcription.
The trp operon contains an operator region where the repressor binds.
RNA polymerase binds to the promotor region.
Acetylcholinesterase is an enzyme, and enzymes are organic catalysts.
NAD+ is the acceptor molecule (co-enzyme) involved in cellular respiration. It accepts hydrogen ions and its electrons to become NADH.
Incorrectly calibrating equipment can contribute to all group’s measurements being incorrect – a systematic error.
Endonucleases (also known as restriction enzymes) are enzymes that cut DNA at specific recognition sequences.
DNA has a slight negative charge that enables it to be attracted to the positive electrode and travel towards that electrode through the gel.
Cas9 plays a part in the immune defence of bacteria against viruses. Its function is to cut the viral DNA into pieces.
In polymerase chain reaction, heating the DNA strand to 95°C breaks the hydrogen bonds and separates the strands, denaturing DNA which makes the strands separate. Then at 60°C, DNA ligase is used to anneal strands of DNA together. Then at 72°C, during extension, a specific DNA polymerase, Taq polymerase, is used during the extension stage of PCR. Taq polymerase is used due to its ability to withstand high temperatures.
ATP hydrolysis (aka ATP catabolism) has the formula ATP + H2O → ADP + Pi + Energy. ATP (adenosine triphosphate) loses a phosphate group (Pi) and becomes ADP (adenosine diphosphate). ATP hydrolysis is an exergonic reaction, meaning it releases energy.
Glycolysis is a series of chemical reactions that break down glucose, a six-carbon sugar, into two molecules of pyruvate. This pyruvate can enter further metabolic pathways, such as the citric acid cycle (Krebs cycle) under aerobic conditions, or fermentation under anaerobic conditions.
DNA ligase forms a phosphodiester bond between the 5’ phosphate group of one DNA fragment and the 3’ hydroxyl group of another. This effectively seals the gap between the two DNA fragments, creating a continuous DNA strand.
When plasmids are modified, after their sequence is determined, they will be cut with a restriction enzyme (liberating sticky ends), which converts it into a linear fragment. The same occurs with the gene of interest and they are then mixed together with DNA ligase to form a recombinant plasmid.
Biofuel is created using microbes that undergo anaerobic fermentation.
The stroma is the site of the light-independent stage of photosynthesis.
As the temperature increases, photosynthesis increases up to a point; beyond this, photosynthesis decreases due to the denaturation of enzymes.
Enzymes can denature, meaning loss of shape and function. Caused by high temperatures, chemicals and pH things.
At low temperatures, the kinetic energy of the enzymes that are involved in photosynthesis decrease.
When the temperature is high, oxygen becomes more likely to bind to Rubisco than carbon dioxide; this results in photorespiration.
Glycolysis breaks down glucose to form two molecules each of pyruvate, ATP and NADH; the latter of which were formed when hydrogen ions were picked up by NAD.
Natural killer cells and cytotoxic T cells destroy virally infected cells by inducing apoptosis.
In photosynthesis, red and violet wavelengths of light carry the energy for the light independent reaction. Once the energy is absorbed the first step is to split water to release oxygen and hydrogen ions. These hydrogen ions move through ATPase to form ATP.
Mucus membranes, non-pathogenic bacteria as well as sweat, tears and saliva form parts of the first line of defence.
In the immune system, natural killer cells and complement proteins are parts of the second line of defence.
The innate immune system is not the adaptive immune system.
The innate immune system includes natural killer cells.
The adaptive immune system includes cytotoxic T cells, specificity, and immunological memory.
Antigen presentation occurs in lymph nodes.
B cells mature in the bone marrow.
T cells mature in the thymus.
Plants can be categorised as C3, C4 or CAM plants.
C3 plants, the most common variety, use the Calvin cycle to fix carbon dioxide directly into a three-carbon compound. Efficient enough in moderate conditions, but they are inefficient - in hot, dry conditions, their stomata close to conserve water, which also prevents CO2 from entering. This leads to the enzyme Rubisco, normally tasked with grabbing CO2, mistakenly grabbing oxygen, this is called photorespiration.
C4 plants have a workaround to the photorespiration problem. They use a special enzyme, PEP carboxylase, to initially fix CO2 into a four-carbon compound in specialized cells. This four-carbon compound is then transported to other cells where the Calvin cycle takes place. This separation of initial carbon fixation and the Calvin cycle effectively concentrates CO2 around RuBisCO, minimizing photorespiration. In C4 plants, the initial carbon fixation happens in mesophyll cells, and the Calvin cycle occurs in bundle sheath cells. It’s a bit like having two separate factories working together, each with its specialized task.
CAM plants stands for Crassulacean Acid Metabolism, is useful for arid environments. These plants take the C4 strategy a step further by time separating the carbon fixation process. They open their stomata at night to take in CO2, converting it into organic acids, and store it until daytime. During the day, they close their stomata to conserve water and use the stored CO2 for photosynthesis.
Cyclosporin is an immune-suppressing agent that enables the recipient to accept the transplanted organ.
If small groups separate from the parent population into unpopulated areas and this is the founder effect.
Homology shows bone structures that are
similar but adapted for different functions. Analogy shows bone structures that are functionally similar.
Index fossils are from a species that existed for a short period of geological time. short-lived, abundant and wide geographic distribution, and are found in limited rock strata.
Antigenic drift specifically refers to the genetic mutations in a virus. Antigenic shift is where genes from different viruses mix.
Bipedalism is the defining distinguishing characteristic between the two taxa, primates and hominins. Opposable thumbs, a large cranium and binocular eyes are shared characteristics between hominins and primates. Hominins only include bipedal ancestors of humans.
In the body, cells that are infected with a virus present the viral antigen on their MHC-II proteins. These antigens can then be identified by lymphocytes as part of the specific immune response. The viral antigen is displayed on the MHC-II protein, which would be recognised by a naïve T cell and triggers the cell-mediated response.
For enzyme inhibitors, non-competitive inhibitors bind outside the enzyme’s active site and change the shape of the active site so that substrate cannot bind to the enzyme. In contrast, a competitive enzyme binds to the active site of the enzyme.
Ribosomes are made of protein and rRNA.
The molecule is tRNA. It brings amino acids to ribosomes and has a distinctive structure, with areas of complementary base pairing and ‘bubbles’ of single stranded unpaired bases.
The set of three nucleotides at the bottom of the tRNA molecule is called an anticodon.
The cerebrum became more folded, allowing greater brain sizes. A larger brain sized has increased alongside social capacity and has greater energy requirements. The sagittal crest has decreased as brain size has grown in Homo sapiens.
Evolutionary timeline, notice that floiwering plants comes last, prokaryotes, eukaryotes, multicellular organisms, water-dwelling animals, the Tiktaalik species, land-dwelling animals, mammals, flowering plants.
Transitional fossils have traits of both the ancestor and derived (recent) species; they often fill evolutionary ‘gaps’ that show relationships between species.
Fossilisation requires rapid coverage by sediment, cool climate, low light, and low oxygen levels.
The iflammatory response includes initiation, vasodilation and migration. In the migration step, complement proteins and phagocytes can enter the site from the bloodstream and combat any pathogens that are present.
Enzyme activity will increase with increasing concentrations of substrate until all of the enzymes are occupied, at which point their activity will plateau.
Disease transmission includes airborne transmission, vector transmission, and faecal-oral transmission.
Peptide hormones include insulin, glucagon, and growth hormone.
Tumour cells express MHC-I on their surface which MHC-1 proteins attach to.
Monoclonal antibodies battle cancer with binding to cancerous cells and marking them as foreign so that they are targeted by natural killer cells, binding to cancerous cells and interacting with complement proteins to form membrane attack complexes, and carrying radioactive isotopes or drugs to cancerous cells by conjugated monoclonal antibodies.
Passive immunity involves obtaining antibodies that are not produced by the patient’s own body. Because there is no exposure to antigens, memory cells are not produced.
The bottleneck effect is when a natural disaster kills off a large portion of the population and changes the allele frequencies in that population.
Gene flow is the movement of alleles between populations.
In bectarial trnasformations, the antibiotic resistance gene is already present in the plasmid and will provide antibiotic resistance to the bacteria that take up the plasmid, whether or not the gene of interest is inserted. This allows scientists to grow and select only bacteria with the plasmid when plated on an antibiotic medium.
Antigenic drift refers to changes in viruses, not bacteria.
Natural selection, overprescribing and stopping a course of antibiotics prematurely, rather than finishing it completely, contribute to antibiotic resistance.
Complement proteins attract phagocytes to pathogens, form membrane attack complexes, and stick to the outside of pathogens to aid recognition.
The light independent reaction of photosynthesis is also known as the Calvin cycle.
Difference between C4 and CAM plants is the timing of the light independent reaction (Calvin cycle). C4 plants does it during the day, and use spatial separation. CAM plants does it during the night.
Mitochonodrai structure. It is double membrane bound. The intermembrane space is the region between the outer and inner membranes, a space with a specific composition crucial for certain processes. The inner membrane is a highly folded and much less permeable membrane. These folds are called cristae, which greatly increase the surface area. The matrix is the space enclosed by the inner membrane. This is the central hub of the mitochondrion, containing the mitochondrial DNA, ribosomes, and enzymes responsible for the citric acid cycle (Krebs cycle) and other metabolic processes.
The mRNA start codon is AUG and stop codons are UAA, UAG, UGA.
After a protein is translated by a ribosome, transport vesicles travel between the rough endoplasmic reticulum and the Golgi apparatus, where proteins are folded and modified, before a secretory vesicle transports the proteins to the plasma membrane for exocytosis
A controlled experiment has a control group and an experimental group.
Transgenic organisms are genetically modified organisms with genes that are introduced from a different species. Usually uses CRISPR-cas9.
The genetic code is universal and degenerate. Degenerate means that more than one codon of can code for an amino acid.
Sympatric speciation is when populations evolve into different species without a geographic barrier in place, like Howea palms.
Allopatric speciation is when populations have geographic barriers and evolve into different species.
Regulatory genes code for proteins that control the expression of structural genes.
When cellular tryptophan levels are low, the genes will be freely expressed (no repression) and the mRNA molecule will not be truncated/shortened (no attenuation).
A termination hairpin will form in mRNA when there are high levels of tryptophan in the cell.
Inserting DNA into a plasmid produces a recombinant plasmid. Any bacteria that take up the recombinant plasmid now have the ability to produce human insulin, an ability they previously did not have. Therefore, the bacteria are referred to as being transformed.
Golgi apparatus and the rough ER are responsible for eynthesis and export of protein things like insulin.
The proteome is the entire set of proteins produced by an organism.
The light-dependent stage supplies ATP and NADPH to the light-independent stage.
When NAD+ accepts an electron from glucose, it becomes NADH, the reduced form of the molecule. The NADH molecule transports this electron to mitochondria where it then donates the electron to oxygen, converting back to NAD+. This occurs during the electron transport chain, which occurs in the cristae of the mitochondria.
Glycolysis is the initial step in the breakdown of glucose, and while it generates some ATP, the majority of the energy remains stored within the pyruvate molecules, ready to be further utilized in subsequent stages of cellular respiration. This energy is further harnessed through subsequent stages of cellular respiration, particularly the citric acid cycle and oxidative phosphorylation, where pyruvate is completely oxidized to carbon dioxide and water.
During fermentation carried out by yeast cells, there is less energy released than by aerobic respiration, produces carbon dioxide and ethanol.
In response to an antigen, if it is the first time the antigen is recognized, primary response happens. It takes days for recognition, and start producing antibodies of low amounts. Primarily IgM antibodies are produced. Some B and T cells deifferentiate into memory cells, making memory. Subsequent encounters with memory antigen trigger a secondary response. Response much faster, high antibody levels, long duration. Primarily IgG antibodies are produced.
Antibiotics have no effect on viruses.
B memory cells remain in the lymphatic system long after an infection. If B memory cells are exposed to an antigen that they recognise, then they will undergo division, producing large numbers of B plasma cells and a few memory cells. The plasma cells are used to produce antibodies.
The difference between antibodies and antibiotics. Antibodies are produced by the plasma cells of the immune system. Targets a specific antigen. Antibiotics are produced synthetically or by microorganisms. Targets and kills some bacteria.
Monoclonal antibodies are laboratory-produced molecules that are engineered to serve like antibodies that restore, enhance, modify or mimic the immune system.
Rheumatoid arthritis is an autoimmune disease where the body’s immune system mistakenly attacks its own tissues, specifically the lining of the joints. Leads to chronic inflammation.
Lymph node swelling is linked to the function of mast cells.
When a foreign substance like a pathogen or allergen enters the body, mast cells residing in the affected tissue become activated. This triggers the release of inflammatory mediators, most notably histamine. Histamine increases blood flow to the area, leading to redness and warmth. This inflammatory response attracts immune cells, like lymphocytes, which accumulate in the lymph nodes. This activity within the lymph node causes it to swell.
A gene pool is the sum total of alleles in a population.
To control the emergence of new strains of viruses, we monitor genetic changes to see if new things emerge. Vaccines don’t relate to virus emergence.
Vestigial structures are those that have lost most or all of their original function in some species.
A homologous structure is one that has common ancestry in multiple organisms.