Photosynthesis Respiration Cell Division Cell Processes Photosynthesis Respiration Cell Division

Autotrophs vs. Heterotrophs Autotrophs (producers): make their own food by using energy from sunlight to produce high energy carbohydrates (sugars/starches) Heterotrophs (consumers): eat food to obtain energy Autotrophs vs. Heterotrophs

All cells are fueled by a chemical energy called ATP (adenosine triphosphate). It is a result of breaking down sugar in cells. adenine ribose phosphates Chemical Energy

White light is a mixture of colors - each color has a different wavelength and a different amount of energy. It can be broken down into its separate colors with a prism. Properties of light

Rainbows are another example of white light being separated Rainbows are another example of white light being separated. Light travels through a water drop and gets bent.

Substances that absorb and reflect wavelengths of light Substances that absorb and reflect wavelengths of light. The color of the pigment is the wavelength of light being reflected, while all the rest are being absorbed. Pigments

Plant pigments Chlorophyll: reflects green Chlorophyll a is light green Chlorophyll b is dark green Xanthophyll: reflects yellow Carotenes: reflects orange Anthocyanins: reflects red Plant pigments

The process of using sunlight energy to make chemical energy Overall equation: 6CO2 + 6H2O --> C6H12O6 +6O2 Which occurs in a series of smaller steps Photosynthesis Sugar stored in plant

Steps in photosynthesis Light dependent reaction: sunlight is absorbed by the pigments in the chloroplast. This energy is used to split water into oxygen and hydrogen. The oxygen is released out of the plant. The remaining hydrogen is also separated into protons and electrons, which continue on to separate reactions where some ATP will be made that will provide the energy to build a sugar molecule. Steps in photosynthesis

The Calvin cycle (dark reaction) is the next step The Calvin cycle (dark reaction) is the next step. CO2 from the air enters the leaf. In a series of reactions the CO2 is used to form a sugar molecule. Calvin Cycle

Respiration is the process of releasing the energy in sugar by breaking the bonds holding it together. In a series of reactions, ATP is formed. This is how energy is created for all life processes. Overall equation: C6H12O6 + 6O2 --> 6CO2 + 6H2O + energy (ATP) Respiration

Steps in cellular respiration Glycolysis: One sugar molecule is broken in half making two 3-carbon molecules and 2ATP. Steps in cellular respiration

Anaerobic respiration Fermentation: oxygen is not present. The two 3-carbon molecules are broken down to individual carbons. Anaerobic respiration

Alcoholic fermentation is done by yeast Alcoholic fermentation is done by yeast. It makes alcohol and carbon dioxide. Bread and alcohol industries Lactic acid fermentation is done by muscle cells. It makes lactic acid and carbon dioxide Lactic acid is toxic and makes your muscles hurt. Examples

If oxygen is present then a process called the Kreb’s cycle occurs instead. The two 3-carbon molecules go through a series of steps of breaking down and recombining until carbon dioxide is released as waste. 34 additional ATP are made. Aerobic respiration

https://www.youtube.com/watch?v=eo5XndJaz-Y Respiration

Cell growth All cells grow in size, but eventually they must divide. DNA overload: the larger the cell, the more demands on the DNA (which does not increase) Material exchange: larger cells are less efficient in moving nutrients and waste across cell membrane. Materials are used up faster than they can be replaced in large cells. Surface area is the amount of cell membrane and volume is the amount of material inside the membrane. The volume increases faster than the surface area as the cell grow. Cell growth

Since smaller cells are more efficient than bigger cells, the cell will divide and form smaller cells. Each division fixes the surface area to volume ratio. Cell division

Cell division is controlled. Not all cells divide at the same rate. Skin and bone cells divide many times throughout our lives Muscle and nerve cells do not divide after they are formed. Chemicals called cyclins regulate when cells can divide. Rates of cell growth

Factors in determining cell division Space: normal cells in a lab experiment grow until they touch each other or the side of a dish Injuries: cells at an injury site are stimulated to divide rapidly so that healing will occur Factors in determining cell division

Cancer Uncontrolled cell division Cells have lost their ability to control cell division. Cancer cells form masses of cells called tumors. Cancer cells do not care about touching each other but will grow until all food is gone Cancer

Chromosomes Condensed, coiled pieces of DNA. They will take into the new cell all the genetic information. Chromosomes

Chromosomes must double in number BEFORE cell division.

Humans have 46 chromosomes

Cell cycle Period from one division to the next Cell division Mitosis is the division of the nucleus Cytokinesis is the division of the cytoplasm Cell cycle

Interphase Time spent between cell divisions G1: cell is growing S: the DNA replicates (copies) G2: the rest of the cell prepares for division Interphase

Steps of Mitosis Prophase: longest stage Chromosomes are visible. 2 centrioles separate and move to opposite sides of the cell. A spindle of microtubules form between them. Steps of Mitosis

Metaphase Shortest stage Chromosomes line up along center of cell (equator) The chromosomes attach to the spindle threads at their centromere Metaphase

The 2 halves of the chromosome pull apart from each other and move along the threads to opposite sides of the cell. Anaphase

Telophase Chromosomes from 2 nuclei The DNA lengthens and disappears from view. Telophase

The cell begins to lengthen in anaphase and splits completely after telophase. Animal cells form a cleavage furrow. Plant cells form a cell plate which becomes a cell wall between them. Cytokinesis

Mitosis is asexual reproduction. The new cells begin interphase and the cell cycle starts all over again. Mitosis is asexual reproduction. All cells will be identical. It is used for growth and repair in the body.

Mitosis in onion cells