Introduction to Life Science PDF

Introduction to Life Science Earth and Life Science Introduction to Life Science Allows us to understand the basis of all living things on Earth. A fundamental part in learning about organisms, including ourselves. Includes how we came about and the basic units of life. The...

Introduction to Life Science Earth and Life Science Introduction to Life Science Allows us to understand the basis of all living things on Earth. A fundamental part in learning about organisms, including ourselves. Includes how we came about and the basic units of life. The Historical Development of the Concept of Life The Historical Development of the Concept of Life Life can be loosely defined as, “any autonomous system with open- ended evolutionary capabilities.” The Historical Development of the Concept of Life Autonomy refers to an organism’s capacity to use matter and energy to create its own components, its relationship with the environment, and the mutual modifications of both. The Historical Development of the Concept of Life Open-ended evolution refers to their ability to continuously adapt and change. The Historical Development of the Concept of Life Biological activity can be found wherever there is an energy source and liquid water. The Historical Development of the Concept of Life At a molecular level, living organisms show a striking biochemical unity. The Historical Development of the Concept of Life Same basic cellular organization, repeated use of genetic matter in the form of DNA, the universal genetic code, and the variations that are found in the same bioenergetics’ mechanisms. The Historical Development of the Concept of Life The explanation for all these suppositions on life is that they come from a common ancestor, which was observed by Charles Darwin. The Historical Development of the Concept of Life Charles Robert Darwin (1809 – 1882) was an English naturalist, geologist, and biologist, most known for his contributions is evolutionary biology. The Historical Development of the Concept of Life Taxonomy is the classification of living and extinct organisms. Term is derived from the Greek words; taxis (arrangement) and nomos (law). The Historical Development of the Concept of Life The domains archaea and bacteria, are both prokaryotes or single-celled organisms. The difference being archaea lives in extreme environments or extremophiles. The Historical Development of the Concept of Life The Historical Development of the Concept of Life Domain eukarya consists of eukaryotes or multi- cellular organisms. The Historical Development of the Concept of Life The Historical Development of the Concept of Life Unique scientific names are used to identify organisms. It consists of an organism’s genus and species. Common name Genus Species Cat Felis catus Lion Panthera leo When writing a scientific name, it should always be italicized and only the genus should start with a capital letter. The Historical Development of the Concept of Life In 1920s, Aleksandr Oparin fathered the notion that when Earth was young, the oceans were filled with simple chemicals important for life. This was known as the primordial soup theory. The Historical Development of the Concept of Life Aleksandr Oparin (1894 – 1980) was a Soviet biochemist notable for his theories about the origins of life, and for his book The Origin of Life. The Historical Development of the Concept of Life In 1953, the primordial soup theory received support when Stanley Miller and Harold Urey conducted the Miller-Urey experiment. The Historical Development of the Concept of Life Stanley Miller (1930 – 2007) was an American chemist most well known for the Miller-Urey experiment. The Historical Development of the Concept of Life Harold Urey (1893 – 1981) was an American physical chemist most well know for his discovery of deuterium. The Historical Development of the Concept of Life Miller mixed four simple chemicals in glass tubes, which were heated and shocked with electrical sparks to mimic lightning. The experiment made several amino acids, the building blocks of proteins. The Historical Development of the Concept of Life In 1988, Gunter Wachterhauser proposed that pyrite was the energy source, as well as the electron source, of all living matter. The Historical Development of the Concept of Life Gunter Wachtershauser (1938) is a German chemist who is widely known for his work on the origin of life. The Historical Development of the Concept of Life Either life started out as a simple system that took advantage of the environment (heterotroph), as proposed by Oparin, or self-sustained systems (autotroph) emerged early on, as proposed by Wachterhauser. The Historical Development of the Concept of Life Another debate is whether genetic material or genes emerged first (proposed by Henry Muller), or whether proteins emerged first (proposed by Leonard Troland). The Historical Development of the Concept of Life Tom Cech and Sydney Altman discovered catalytic RNA (ribonucleic acid), which forms proteins from genetic material. Those who contest the replicators argue that there is no way to efficiently use energy without the necessary proteins. Which is why several scientists advocated for the emergence of primitive, self-catalytic metabolic networks as the primary step towards the creation of replicators. Unifying Themes in the Study of Life Unifying Themes in the Study of Life Reductionism is the approach of breaking down larger systems into simpler systems that are more manageable to study. Unifying Themes in the Study of Life Emergent properties are those that arise through interactions among smaller parts that do not exhibit such properties when they’re alone. Unifying Themes in the Study of Life Cellular Level: Atoms > Molecules > Organelles > Cells Organismal Level: Tissues > Organs > Organ Systems > Organism Population Level: Population > Species > Biological Community Ecosystem Level: Biological Community + Physical Habitat The Biosphere: The entire planet thought of as an ecosystem Unifying Themes in the Study of Life Systems biology is a system that combines components that function together. Unifying Themes in the Study of Life Structure and Function states that an organism’s form must fit its function. For example, a monkey’s foot is designed for holding on to tree branches. Analyzing an organism’s structure gives clues as to how it works, and analyzing its function can give clues as to how it was constructed. Unifying Themes in the Study of Life The Cell is the basic unit of life structure and function. Understanding how cells work is a major focus of research endeavors in biology. Unifying Themes in the Study of Life Eukaryotes are multi-cellular and contains organelles in their cytoplasm, while prokaryotes are unicellular and does not contain organelles in their cytoplasm. Unifying Themes in the Study of Life Genes are the basic units of inheritance that transmits genetic information from parent to offspring, it is made up of a sequence of DNA. Deoxyribonucleic acid or DNA is the storage space for genetic information. Unifying Themes in the Study of Life It is composed of the building block of genetic information called nucleic acids which are; adenine (A) and thymine (T), guanine (G) and cytosine (C). Unifying Themes in the Study of Life DNA also controls the production of proteins through ribonucleic acid or RNA. In RNA, adenine is paired with uracil instead of thymine. Transcribing genetic information to proteins is called gene expression. Unifying Themes in the Study of Life A fundamental characteristic of all living things is that they use energy to carry out their activities, and to sustain them. Living organisms function to transform the type of energy. Unifying Themes in the Study of Life Ecosystem encompasses an organism’s interaction with the physical environment and other organisms. Unifying Themes in the Study of Life Biological processes regulate themselves through a mechanism called feedback regulation. The chemical pathway contains several steps, and each step is controlled by an enzyme. Unifying Themes in the Study of Life Positive feedback occurs when the product speeds up its own production. Meanwhile, negative feedback occurs when the accumulation of the product halts the chemical process. Unifying Themes in the Study of Life Organisms exhibit the diversity as well as the unity of evolution. Living organisms have shared traits, yet each organism is suited to its environment.