The APsolute RecAP: Biology Edition

The cell cycle consists of interphase, mitosis and cytokinesis.(1:33) There are a number of internal checkpoints that regulate a cell's progression through the cell cycle, including cyclins(4:23) and Cdk complexes(5:23). These couple with phosphorylation to activate target proteins throughout the cell cycle. The Question of the Day asks (7:38) Some cells, like neurons, exit the cell cycle prior to...

If you are ever lucky enough to have a major scientific discovery, you’d probably name it after yourself too. Melanie recaps each scientist's background (1:05) (4:26) before discussing the main events of the Calvin Cycle (1:40) and Krebs Cycle (5:02). The Calvin cycle forms sugars in the stroma of chloroplasts while the Krebs cycle oxidizes sugars in the matrix of mitochondria. The Question of the...

Like Pacman, enzymes have specific shapes, act on smaller molecules and can be destroyed by external factors. Enzymes are made of proteins - each having a unique structure for a specific function.(1:10) Melanie explains lactose intolerance (3:30) before straightening her hair for a night out (5:43). There are several environmental factors which influence enzyme functioning (6:41). Disrupt those hy...

Electrons are going to enter a membranous pinball machine in episode 57. The electron transport chain is found in the process of photosynthesis (2:10) and the process of cellular respiration.(4:30) This recap will first focus on structure and function for each respective organelle before drawing similarities (7:34) and pointing out differences. The episode concludes with unit connections and exam...

Let’s put our sneakers on and go for a run while listening to Episode 56! Melanie begins by debunking some myths to make our chemistry and physics colleagues happy (1:30). Next, remember key activation energy concepts (2:43). Lastly, analyze two graphs to distinguish between energy storing and energy releasing reactions (4:36). The Question of the Day asks (8:02) True or False? ΔG is constant in c...

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)....

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: Bi...

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 s...

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...

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...

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...

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...

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 storag...

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). Pr...

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 Qu...

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 da...

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...

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...

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 ev...

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 disti...

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 th...

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 ann...

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 r...

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...

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 (...