Episode 55 recAPs the gummy bear experiment with potassium chloride - combustion! Combustion reactions are one subclass of oxidation-reduction reactions, or redox reactions for short. (1:00) Why aren’t our cells bursting into flames during cellular respiration?(4:08) Glucose is gradually oxidized through several steps during the process of glycolysis, pyruvate oxidation and the Krebs cycle (5:37). The Question of the Day asks (8:03) Glucose is oxidized, what molecule is reduced in cellular respi...
Nov 05, 2020•9 min•Ep. 55
It's important that cell membranes establish and maintain their internal environments through selective permeability.(1:40) There are three main types of active transport - membrane pumps,(2:45) endocytosis (5:37) and exocytosis.(6:30) The Question of the Day asks (8:10) How is a cotransporter classified that moves molecules in opposite directions? Thank you for listening to The APsolute RecAP: Biology Edition! (AP is a registered trademark of the College Board and is not affiliated with The APs...
Oct 28, 2020•9 min•Ep. 54
Episode 53 brings biology, physics and chemistry all together to answer this age old question - why did the fart cross the room? Melanie begins by recapping the fluid mosaic model and kinetic energy (2:19). To get across the plasma membrane without the use of energy there are two options - sneak in between the phospholipids themselves (3:40) or use a transport protein (6:50). It's true - whoever smelt it most likely dealt it as solutes diffuse from high to low concentration. The Question of the ...
Oct 21, 2020•10 min•Ep. 53
The movement of materials through the endomembrane system is consistent through all eukaryotic cells. The episode begins with a wording deep dive (1:12) before some molecular story time (2:25). The endomembrane system includes the nuclear envelope, lysosomes, vesicles, endoplasmic reticulum, Golgi apparatus and plasma membrane (4:16). Melanie concludes the episode with unit and exam connections (5:50). The Question of the Day asks (7:00) What is the internal space of the folded Golgi cisternae c...
Oct 14, 2020•8 min•Ep. 52
Remember when Pluto was a planet? Scientists continually restructure their way of thinking as they obtain more data. Taxonomy is the science of naming organisms while phylogeny groups them based on evolutionary relationships (1:16). King Phillip wasn’t always so dull, but as microscopic life was discovered, the manner of classifying and sorting organisms needed updating (2:38). Primary differences between domains and kingdoms are cell type, DNA organization, organelles, energy acquisition and ce...
Oct 07, 2020•9 min•Ep. 51
All living things are categorized into one of two cell types: prokaryotes and eukaryotes. Melanie begins Episode 50 with a nerdy word dive (1:13) before distinguishing between prokaryotic and eukaryotic cells (2:04). Settle in for endosymbiosis story time!(5:02) The episode wraps up with unit connections and exam expectations (6:42). The Question of the Day asks (7:58) The liver has many functions, one of which is to process alcohol and detoxify the blood. Which organelle would you expect to fin...
Sep 30, 2020•9 min•Ep. 50
Episode 49 recaps these very diverse group of hydrophobic, nonpolar molecules. Although all containing the elements C, H and O (1:10), lipids are categorized into distinct groups: fats (2:00), waxes (4:00), phospholipids (4:40) and steroids (5:48). Can you distinguish between a saturated and unsaturated fatty acid chain? Melanie wraps up the episode with Unit Connections and describes several exam exclusions (6:08). The Question of the Day asks (7:20) Besides lipids, what other group of biologic...
Sep 23, 2020•8 min•Ep. 49
Formed by autotrophs and disassembled by nearly all living things - carbohydrates are the primary source of chemical energy for the cell. The elements carbon, hydrogen and oxygen are generally found in a 1:2:1 ratio in a carbohydrate (1:00). Carbohydrates primary function is to serve as a cellular fuel as monosaccharides (1:30) and disaccharides (2:46) whereas polysaccharides provide energy storage and structural support (3:38). It is important for organisms to have an appropriate amount of gluc...
Sep 16, 2020•7 min•Ep. 48
While the traditional health food pyramid has really gone out the window, there is little argument that lean proteins are essential to a balanced diet. Proteins were almost crowned king of the biological molecules during the quest for heredity (1:06). Their diversity in structure is the greatest of all the biological molecules (2:35) with four levels as it bends and folds in upon itself (4:22). Proteins have a variety of functions, such as support, transport, recognition, movement, and communica...
Sep 09, 2020•9 min•Ep. 47
Biology returns with Season 2! Thank you for helping us reach 31,000 downloads. Make sure to check out our website for more courses, episode study guides, virtual classrooms and tutoring (1:00). Support your favorite podcast and rock a nerdy t-shirt with our newly launched merch! (2:20) You can expect season two to take a deeper dive into cross-unit topics and integrate FRQ practice. (2:50) The Question of the Day asks (3:23) When is the 2021 AP Biology exam? Thank you for listening to The APsol...
Aug 12, 2020•4 min•Ep. 46
Melanie ventures into the aftermath of a zombie apocalypse in Episode 45. Life always finds a way. The genetic variations organisms have are random - accumulated through mutation and other meiotic chance (1:43). Competition and cooperation are important aspects of biological systems - but the playing field isn’t fair when an invasive species shows up (2:40). Who knew mussels could cause so much damage? (4:15) Humans haven’t been the kindest to the environment and our impact on ecosystems is well...
Jun 12, 2020•9 min•Ep. 45
Population ecology is the study of factors that affect a population and how and why a population changes over time. Individual organisms interact with one another and with the environment in very complex ways (1:40). Population growth dynamics depend on a number of factors (2:30) and may result in exponential or logarithmic growth. if the ecosystem stays relatively stable, we can expect the growth rate to also stay the same. But upset the apple cart with other influencing factors, floods, famine...
Jun 10, 2020•8 min•Ep. 44
We require a constant input of energy to maintain organization, grow and reproduce. Some organisms are able to maintain their body temperature internally, whereas others rely on the environment (1:15). Organisms have evolved unique reproductive strategies in response to energy availability (2:40). A net gain in energy results in energy storage or growth whereas a net loss of energy results in loss of mass and, ultimately, the death of an organism (3:40). In the natural world, organisms need maxi...
Jun 08, 2020•7 min•Ep. 43
Isn’t evolution “just” a theory? Scientific theories are broadly accepted, combine multiple hypotheses and an abundance of evidence to explain a phenomenon about the natural world. Episode 42 recAPs the multitude of evidence supporting the theory of evolution. Zoom in to review biogeography (2:14), the fossil record (3:00), homologous structures (4:00) vestigial structures (4:55), and molecular evidence (5:38). The Question of the Day asks (7:20) What was the superocean called from Wegener’s Con...
Jun 05, 2020•8 min•Ep. 42
Episode 41 recAPs the random side of evolution. Melanie begins with a vocab review - allele, gene, heterozygous (1:00). This episode is about population genetics because populations are the level of ecological organization where evolution occurs (1:40). Mutations are the primary source of genetic variation, providing new phenotypes on which natural selection can act (2:40). It's important to distinguish between gene flow and genetic drift (3:24). Two types of genetic drift are the bottleneck eff...
Jun 03, 2020•7 min•Ep. 41
Episode 40 recAPs Chucky D and Natural Selection. “Nothing in biology makes sense, except in the light of evolution” (1:30). Charles Darwin was not the first to propose the theory of natural selection (2:00). Competition for limited resources results in differential survival and reproduction (3:00). #thestruggleisreal. Pesticide resistance models natural selection action (4:30). The Question of the Day asks (6:12) “Which finch phenotype did Darwin most study?” Thank you for listening to The APso...
Jun 01, 2020•7 min•Ep. 40
Melanie recAPs the 2020 AP Bio Exam experience in Episode 39. The exam included two FRQs with differential weighting and three different submission options (1:00). The exam had several levels of test security (2:20). The AP exams are scored on a scale of 1 to 5 and are not curved (3:00). You earn points for correctly responding to every action verb in the question (4:15). The College Board has announced an Exception Testing window! (5:00). Third times a charm? The Question of the Day asks (5:52)...
May 29, 2020•7 min•Ep. 39
Episode 38 is our second listener’s choice recAP from Instagram topic requests. Pedigrees are used to study the pattern of inheritance of a particular trait through several generations in a family (1:20). Signal transduction pathways link signal reception of a ligand with a cellular response through phosphorylation (2:38). Cellular respiration oxidizes glucose to form ATP (3:30). Eukaryotic gene regulation occurs throughout the central dogma (4:50). Successful FRQ writing involves intentional ap...
May 15, 2020•8 min•Ep. 38
Sexual reproduction increases genetic diversity in Episode 37. Chromosomes are tightly coiled DNA (1:00) and organized in homologous pairs (1:45). The three primary sources of variation within the population are chromosome segregation, independent assortment, and random fertilization (2:15). Do you remember Mendel’s laws? Some chromosomal errors cause genetic disorders (3:20). We can use pedigrees to find patterns in genetic traits (4:20). The Question of the Day asks (5:42) “During what phase o...
May 13, 2020•7 min•Ep. 37
It’s all about maintaining homeostasis in Episode 36! Neurons are specialized cells for conducting electrical signals and releasing chemical neurotransmitters (2:02). Axons conduct an action potential through the movement of sodium and potassium ions (3:00). The message changes from electrical to chemical at a synapse (4:30). Neurotransmitters act as ligands, binding to the postsynaptic membrane (5:20). The Question of the Day asks (6:44) “Which autoimmune disorder degrades the myelin sheath of ...
May 11, 2020•8 min•Ep. 36
Episode 35 reviews graphing essentials and the relationship to energy. It's important to use the most appropriate graph for the data set (1:10). Do you remember DRY MIX TAILS? (1:50) Energy can be transferred and transformed, but not created or destroyed. (3:00) Imagine yourself walking along an energy graph, over the activation energy hill, and then either up to a plateau for endergonic or down to a valley for exergonic reactions (4:20). Match each graph with a reaction you are already familiar...
May 08, 2020•7 min•Ep. 35
Episode 34 finds the similarities and differences between chloroplasts and mitochondria. The endosymbiosis theory states that these energy transducers were once independent prokaryotes (1:38). Chloroplasts capture light energy in photosynthesis (2:20). Mitochondria break down sugars in cellular respiration (4:00). There are many commonalities between each organelle’s structure and function. The Question of the Day asks (6:35) “What are the alternate names for the Krebs cycle”? Thank you for list...
May 06, 2020•8 min•Ep. 34
Episode 33 recAPs genetic engineering techniques of biotechnology. Electrophoresis separates molecular fragments according to size and charge visually (1:00). PCR amplifies DNA fragments, making thousands of copies from even the smallest sample (2:35). Bacterial transformation introduces foreign DNA into bacterial cells (4:00). DNA sequencing is a part of biotechnology, but typically not working with an entire genome at one time (6:15). The Question of the Day asks (8:08) “Which cells in the hum...
May 04, 2020•9 min•Ep. 33
It’s the battle of the nucleic acids in Episode 32! DNA may have all the information, but RNA does all the work. DNA and RNA are made of nucleotide monomers (1:05). DNA and RNA nucleotides differ in their pentose sugar (1:55) and pyrimidine base ( 3:00). DNA forms an antiparallel double helix (3:50) compared to the single strand RNA (5:05), forming mRNA, rRNA and tRNA. The Question of the Day asks (6:44) “Nucleic acids are one of two biological molecules that contain the element nitrogen. What i...
May 01, 2020•8 min•Ep. 32
You hear mutations - but we hear variation! Mutations have several causes and can be positive, neutral or negative to the phenotype. Grab a recap of the Central Dogma before diving in (1:40). Distinguish between point mutations and frameshift mutations (2:50). Mutations have a strong correlation to evolution(3:40). Prokaryotes have been around a long time, with many reproductive techniques (5:08). Genotypic changes are also the result of errors in cell division, as with non-disjunction (5:40). T...
Apr 29, 2020•8 min•Ep. 31
“Water water everywhere, nor any drop to drink.” Episode 30 reviews the passive transport of water and the calculation of water potential - with many water sound effects! Hypertonic solutions have a greater concentration of solutes than a hypotonic solution (1:30). It does not end well for a paramecium placed in freshwater (2:15). Water potential allows us to predict the movement of water (4:00) and is measured in bars. Don’t memorize any equations! (5:20) The Question of the Day asks (6:56) “Wh...
Apr 27, 2020•8 min•Ep. 30
Melanie wants you to be prepared and calm on May 18th! Episode 29 recAPs test taking tips appropriate to the digital platform. You need to practice timed FRQs in the same location and with the same resources as exam day (1:06). Stop studying and go to bed! (1:45) You can either type or hand write your responses, but don’t work in the redzone (2:40). Keep scrap paper, a calculator and minimal resources nearby during the test (3:50) There won’t be much time to look up answers. Make sure you addres...
Apr 24, 2020•8 min•Ep. 29
Episode 28 recAPs some of the great scientific minds of history. Atoms are the building blocks of matter, with work by greats such as Dalton, Rutherford, and Bohr (1:08). Gregor Mendel is now renowned as the father of heredity, but began as a pea farmer (2:30). DNA was identified as the molecule of heredity by comparing chemical properties through experiments by Griffith, Avery, Hershey and Chase (3:28). You likely remember Watson and Crick’s double helix model, but what about Franklin and Charg...
Apr 22, 2020•8 min•Ep. 28
Episode 27 recaps the connection between the coronavirus and the content on the AP Bio exam. Viruses are nonliving agents (1:05) with a hijacking infection strategy. Coronaviruses are named for their club-like proteins sticking out from the surface (2:45). The viral RNA genome is translated by host cell ribosomes (4:20). Biotechnology, like PCR, is used to test for viral presence in test swabs (5:20). Viral genomes are able to evolve over time, with high mutation rates (5:55). The Question of th...
Apr 20, 2020•8 min•Ep. 27
Episode 26 is our first listener’s choice episode! The first recAP is about membrane proteins - both structure and function (1:18). Second, a biotechnology refresher with discussion of bacterial transformation, electrophoresis, and PCR (3:10). Lastly, Melanie reviews each scientist’s contribution to the discovery of DNA as the hereditary molecule (5:51). The Question of the Day asks (7:40) “What percentage of DNA is made of nitrogen?” Thank you for listening to The APsolute RecAP: Biology Editio...
Apr 17, 2020•9 min•Ep. 26
