Organization and Patterns of Life

Life is dependent upon availability of an energy source and raw materials that are used in the basic enzyme-controlled biochemical processes of living organisms.

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ORGANIC AND INORGANIC MOLECULES

1.2h Many organic and inorganic substances dissolved in cells allow necessary chemical reactions to take place in order to maintain life. Large organic food molecules such as proteins and starches must initially be broken down (digested to amino acids and simple sugars respectively), in order to enter cells. Once nutrients enter a cell, the cell will use them as building blocks in the synthesis of compounds necessary for life.

Hank talks about the molecules that make up every living thing - carbohydrates, lipids, and proteins - and how we find them in our environment and in the food that we eat. Crash Course Biology is now available on DVD!
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BIOLOGICAL PROTEINS

5.1c In all organisms, organic compounds can be used to assemble other molecules such as proteins, DNA, starch, and fats. The chemical energy stored in bonds can be used as a source of energy for life processes.

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ENZYMES

5.1f Biochemical processes, both breakdown and synthesis, are made possible by a large set of biological catalysts called enzymes. Enzymes can affect the rates of chemical change. The rate at which enzymes work can be influence by internal environmental factors such as pH and temperature.

5.1g Enzymes and other molecules, such as hormones, receptor molecules, and antibodies, have specific shapes that influence both how they function and how they interact with other molecules.

Hank tells us about the city of Eukaryopolis - the animal cell that is responsible for all the cool things that happen in our bodies. Crash Course Biology is now available on DVD! http://dftba.com/product/1av/CrashCourse-Biology-The-Complete-Series-DVD-Set Like SciShow on Facebook: http://www.facebook.com/scishow Follow SciShow on Twitter: http://www.twitter.com/scishow More info.
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CELL THEORY

1.2f Cells have particular structures that perform specific jobs. These structures perform the actual work of the cell. Just as systems are coordinated and work together, cell parts must also be coordinated and work together.

1.2i Inside the cell a variety of specialized structures, formed from many different molecules, carry out the transport of materials (cytoplasm), extraction of energy from nutrients (mitochondria), protein building (ribosomes), waste disposal (cell membrane), storage (vacuole), and information storage (nucleus).

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CELLS

1.2g Each cell is covered by a membrane that performs a number of important functions for the cell. These include: separation from its outside environment, controlling which molecules enter and leave the cell, and recognition of chemical signals. The process of diffusion and active transport are important in the movement of materials in and out of cells.

Hank describes how cells regulate their contents and communicate with one another via mechanisms within the cell membrane. Crash Course Biology is now available on DVD! http://dftba.com/product/1av/CrashCourse-Biology-The-Complete-Series-DVD-Set Like CrashCourse on Facebook: http://www.facebook.com/youtubecrashcourse Follow CrashCourse on Twitter: http://www.twitter.com/thecrashcourse "Concert" music used with permission from Chameleon Circuit.
Hank explains the extremely complex series of reactions whereby plants feed themselves on sunlight, carbon dioxide and water, and also create some by products we're pretty fond of as well. Crash Course Biology is now available on DVD!
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PHOTOSYNTHESIS

5.1a The energy for life comes primarily from the Sun. Photosynthesis provides a vital connection between the Sun and the energy needs of living systems.

5.1b Plant cells and some one-celled organisms contain chloroplasts, the site of photosynthesis. The process of photosynthesis uses solar energy to combine the inorganic molecules carbon dioxide and water into energy-rich organic compounds (e.g., glucose) and release oxygen to the environment.

In which Hank does some push ups for science and describes the "economy" of cellular respiration and the various processes whereby our bodies create energy in the form of ATP. Crash Course Biology is now available on DVD!