Important Figures in Biology PDF

8/27/24, 8:19 PM Platform | Study Fetch Important Figures in Biology (00:25 - 00:58) Robert Hooke: Primarily a physicist and physical science expert Published a book explaining his observations through telescopes and micros...

8/27/24, 8:19 PM Platform | Study Fetch Important Figures in Biology (00:25 - 00:58) Robert Hooke: Primarily a physicist and physical science expert Published a book explaining his observations through telescopes and microscopes Coined the term "cell" after observing the structure of a fungus (Mor) under a microscope Considered one of the fathers of microscopy Antony Van Leeuwenhoek: One of the fathers of microbiology Described what he saw as "little animals" through his microscope Spent a lot of time characterizing and observing the behavior and movement of these "little animals" (which we now know as protists) under the microscope Matthias Schleiden: One of the first people to think about the concept of scaling from microbiology Fundamental Theories in Biology (01:29 - 01:40) Matthias Schleiden was one of the first people to think about the concept of scaling from microbiology. Cell Theory (01:40 - 02:00) Key Points: Cells are the fundamental unit of life All living organisms are composed of one or more cells Cells arise from pre-existing cells Contributions: Robert Hooke: Coined the term "cell" after observing the structure of a fungus Matthias Schleiden: Proposed that all plants are composed of cells Theodor Schwann: Proposed that all animals are composed of cells Rudolf Virchow: Proposed that all cells arise from pre-existing cells ("Omnis cellula e cellula") Atomic Theory (02:00 - 02:30) Key Points: Matter is composed of tiny, indivisible particles called atoms Atoms of the same element are identical, while atoms of different elements have different properties Atoms can combine to form molecules Contributions: https://www.studyfetch.com/platform/studyset/66cd116dd279f5220d947c66/material/66ce6bc7e81bb65113fe36ac/document?go=note 1/6 8/27/24, 8:19 PM Platform | Study Fetch John Dalton: Proposed the modern atomic theory Ernest Rutherford: Discovered the structure of the atom, with a dense, positively charged nucleus surrounded by orbiting electrons Cell Membrane and Transport (02:30 - 03:00) Key Points: Cell membranes are selectively permeable, allowing some substances to pass through while blocking others Cells use various mechanisms to transport materials across the cell membrane, including: Diffusion Osmosis Active transport Importance: Cell membranes and transport processes are crucial for maintaining homeostasis and supporting cellular functions Cellular Respiration (03:00 - 03:30) Key Points: Cellular respiration is the process by which cells convert the chemical energy stored in glucose into a form that the cell can use, ATP This process involves a series of reactions, including glycolysis, the citric acid cycle, and the electron transport chain Cellular respiration can occur with or without oxygen (aerobic and anaerobic respiration) Significance: Cellular respiration is the primary means by which cells obtain the energy they need to carry out their functions Photosynthesis (03:30 - 04:00) Key Points: Photosynthesis is the process by which plants and some other organisms use the energy from sunlight to convert carbon dioxide and water into glucose and oxygen This process occurs in the chloroplasts of plant cells and involves two main stages: the light-dependent reactions and the light-independent (Calvin) cycle Photosynthesis is the foundation of most food chains and food webs on Earth Importance: Photosynthesis is the primary means by which organisms obtain the energy they need to survive and grow https://www.studyfetch.com/platform/studyset/66cd116dd279f5220d947c66/material/66ce6bc7e81bb65113fe36ac/document?go=note 2/6 8/27/24, 8:19 PM Platform | Study Fetch The Cell Theory (00:01:40 - 00:02:08) Previous scientists had known about and started realizing the existence of smaller living things like bacteria and fungi, but it took over 100 years for people to recognize that all living things, including large animals, are made of cells. Matthias Schlein is credited with first coming up with the idea of the cell and highlighting the importance of the cell nucleus. Fundamental Theories of Cells (00:02:19 - 00:02:31) The cell theory is important to understand, and can be summarized by the mnemonic "Important B CD E": Independent Basic unit of structure and function Chemical composition Development Existence (00:02:31 - 00:02:44) All living things are made up of cells All cells come from pre-existing cells Cells are the basic unit of structure and function for organisms (00:02:44 - 00:02:57) All cells have the same chemical composition within a similar species This can change when going from plants to animals Distinguishing Characteristics of Living Organisms (00:03:11 - 00:03:28) The chemical composition between different species is the same - they all contain DNA Cells contain hereditary information and energy flow Energy flow and metabolism occur within living organisms themselves Viruses are not considered fully "alive" because they do not fulfill all the criteria for living organisms, although they do contain hereditary information Viruses and the Criteria for Life (00:03:28 - 00:03:47) Viruses contain hereditary information and have the same basic chemical composition as living organisms Viruses come from other viruses, but they do not have their own metabolism Because viruses lack their own metabolism, they are not considered fully "alive" https://www.studyfetch.com/platform/studyset/66cd116dd279f5220d947c66/material/66ce6bc7e81bb65113fe36ac/document?go=note 3/6 8/27/24, 8:19 PM Platform | Study Fetch The Central Dogma of Genetics (00:03:47 - 00:03:59) The central dogma of genetics states that DNA leads to the encoding of RNA, which then leads to the encoding of proteins This is an important distinction for understanding the flow of genetic information Regulation of Gene Expression (00:03:59 - 00:04:18) DNA has many regulatory sequences and other elements that affect when a particular gene is turned on or expressed The central dogma of genetics (DNA → RNA → Protein) is a fundamental concept in understanding how genetic information is expressed and regulated Genetic Information and Protein Synthesis (00:04:18 - 00:04:43) DNA contains the genetic information that is used to encode RNA and ultimately, proteins The process of gene expression involves the transcription of DNA into RNA, and the translation of RNA into proteins Regulatory sequences and other elements in the DNA can affect the timing and level of gene expression The Central Dogma of Molecular Biology (00:04:43 - 00:04:58) The regulatory sequence of a gene includes the promoter, enhancer, and silencer. Transcription factors and enhancer complexes can bind to the regulatory sequence and turn on RNA polymerase. Once RNA polymerase begins, it leads to the creation of transcription. (00:04:58 - 00:05:11) The RNA molecule produced during transcription will contain introns and exons. Post-transcriptional modifications, such as the addition of a 5' cap and a poly-A tail, will produce the finalized mRNA. The introns will be cut out, and the 5' cap and poly-A tail will be added to ensure the stability of the mRNA. The mature mRNA will then leave the nucleus and bind to a ribosome. (00:05:11 - 00:05:28) In the ribosome, translation will occur, where the mRNA is decoded into a sequence of amino acids. The amino acids will bind together to form a polypeptide chain. The polypeptide chain will then be folded and modified in the endoplasmic reticulum (ER) and Golgi apparatus. (00:05:28 - 00:05:49) The final, modified polypeptide is the finished protein product. https://www.studyfetch.com/platform/studyset/66cd116dd279f5220d947c66/material/66ce6bc7e81bb65113fe36ac/document?go=note 4/6 8/27/24, 8:19 PM Platform | Study Fetch The central dogma of molecular biology states that the flow of genetic information is from DNA to RNA to protein. (00:05:49 - 00:06:00) The RNA world hypothesis suggests that RNA was the initial information carrier in the evolution of life. Key Terms and Concepts: Regulatory Sequence: Promoter Enhancer Silencer Transcription: RNA polymerase Introns Exons Post-transcriptional modifications 5' cap Poly-A tail Translation: Ribosome Amino acids Polypeptide chain Folding and modification in ER and Golgi Central Dogma: DNA → RNA → Protein RNA world hypothesis The Origin of Life: From RNA to DNA and Proteins (00:06:00 - 00:06:12) RNA was the first self-replicating molecule to form from inorganic sources RNA can have catalytic activity and serve as an enzyme (ribozymes) RNA-based systems are less relevant in mammalian systems, but they do exist (00:06:12 - 00:06:33) The RNA eventually became encapsulated or surrounded by a membrane The contents of this micro-environment continued to change and adapt over time This evolution led to the emergence of DNA as a more stable genetic template (00:06:33 - 00:06:46) DNA became the preferred genetic material because it is more stable than RNA The loss of the hydroxyl group in DNA increased the stability of this polymer https://www.studyfetch.com/platform/studyset/66cd116dd279f5220d947c66/material/66ce6bc7e81bb65113fe36ac/document?go=note 5/6 8/27/24, 8:19 PM Platform | Study Fetch (00:06:46 - 00:07:08) Proteins eventually became the dominant means by which cellular processes are catalyzed and structures are maintained This is the hypothesis and theory of how cells developed and how DNA and proteins came to be the mechanisms by which organisms survive and live Key Points: RNA was the first self-replicating molecule, with catalytic activity RNA eventually became encapsulated in a membrane and the micro-environment continued to evolve DNA emerged as a more stable genetic template compared to RNA Proteins became the dominant means of catalyzing cellular processes and maintaining structure "And then eventually DNA became the template because DNA is is much more stable than RN A. So that change was, was eventually made uh the the loss of that hydroxyl group in order to increase the stability of this polymer." Molecule Key Characteristics RNA Self-replicating, catalytic activity DNA More stable genetic template Proteins Dominant catalysts and structural components The hypothesis and theory of how cells developed and how DNA and proteins came to be the mechanisms by which organisms survive and live. https://www.studyfetch.com/platform/studyset/66cd116dd279f5220d947c66/material/66ce6bc7e81bb65113fe36ac/document?go=note 6/6