Term | Definition |
autotrophs | organisms that use sunlight or form chemical bonds in inorganic substances to make energy |
photosynthesis | the process of converting light energy into chemical energy that usually takes the form of carbohydrates |
heterotrophs | animals that get their energy from food or other organisms |
biochemical pathway | the series of chemical reactions linked by what each organism gets its energy from (picture on page 113) |
cellular respiration | how the cells use the water, oxygen, and carbon-dioxide compounds created in photosynthesis |
light reactions | the first stage of photosynthesis and is named because it requires light to happen |
pigments | compounds that absorb light |
chlorophyll | several different pigments located in the thylakoid; the most common types are chlorophyll A and chlorophyll B |
carotenoids | accessory pigments found in the thylakoid that help capture more energy from the light |
photosytem | the individual clusters of pigment molecules and the proteins in the pigment molecules; there are two types known as photosystem 1 and photosystem 2 |
electron transport chain | molecules in the thylakoid membrane that transfer molecules from one molecule to another |
chemiosmosis | a crucial part of the light reactions that is the synthesis of ATP |
ATP synthaze | is an enzyme in the thylakoid membrane that harnesses the energy by making ATP |
calvin cycle | a series of chemical reactions that are assisted by enzymes and is able to produce a three-carbon sugar |
calvin fixation | the incorporation of CO2 into organic compounds
3. Three carbon molecules have to enter the calvin cycle for three-carbon sugars that make organic compounds to be produced. |
stomata | small pores that are usually located in the undersurface of leaves (plants can lose water through these) |
C4 pathway | an alternative pathway that causes plants to have specific enzymes that change CO2 into four-carbon compounds no matter if the carbon level is low or high. |
CAM pathway | the plants that use this open their stomata in the night and close them during the day. The CAM plants take in CO2 at night and put it into different compounds to enter the Calvin Cycle. |
cellular respiration | the process in which cells make ATP by breaking down organic compounds |
glycolysis | the first stage of cellular respiration where organic compounds are converted into pyruvic acid and it produces a small amount of ATP and NADH (an electron carrier molecule). |
aerobic respiration | when a large amount of ATP is made by breaking down pyruvic acid (this process requires oxygen). |
fermentation | an additional pathway to glycolysis that creates NAD+ that occurs when there is no oxygen present. |
lactic acid fermentation | a type of fermentation that occurs when an enzyme converts pyruvic acid that was made during glycolysis into a three-carbon compound called lactic acid. |
alcoholic fermentation | a type of fermentation that occurs when pyruvic acid is converted into ethyl alcohol. (Some plants and unicellular organisms go through this process such as yeast.) |
chromosomes | rod shaped structures made of DNA and proteins |
histones | proteins that the DNA wraps around to help maintain the shape of the DNA and help it be able to save space for packing |
chromatid | each half of the chromosome |
centromere | the center of the chromosome where the two chromatids meet and it holds them together until cell division |
chromatin | the less tightly coiled DNA-protein |
sex chromosomes | chromosomes that determine the gender of an organism and they carry other characteristics |
autosomes | all of the other chromosomes that are not sex chromosomes |
homologous chromosomes | the two copies of each autosome |
karyotype | a photomicrograph of the chromosomes in a normal dividing cell found in a human |
diploid | cells having two sets of chromosomes |
haploid | cells that have only one set of chromosomes (some examples are sperm and egg cells) |
binary fission | the division of prokaryotic cells into two different cells |
mitosis | a type of cell division where the genetic material of the new cell is the same as the parent cell |
asexual reproduction | the reproduction of offspring from one parent |
meiosis | the second type of cell division where the chromosome matters are reduced by half and they can join with another haploid cell to become a diploid cell. |
gametes | haploid reproductive cells |
cell cycle | the repeating set of events in the life of a cell |
interphase | the time between cell divisions and there are 3 phases (G1,S,G2) |
cytokinesis | the division of the cell’s cytoplasm |
prophase | the first stage of mitosis where the DNA coils into chromosomes and they are copied |
spindle fibers | fibers made of microtubules that radiate from the centrosomes and prepare the cell for division |
metaphase | the second stage of mitosis where the spindle fibers move to the center of the cell and attaches to the chromosomes |
anaphase | the stage where the cell begins to divide by pulling the chromosomes apart and the cell divides |
telophase | the last stage where the cells have split and the chromosomes become chromatin while organelles form identically in each of the two cells |
cleavage furrow | when the cytoplasm splits and it separates into two cells |
cell plate | the plate that will eventually become the cell wall and officially create two cells |
cell growth g1 checkpoint | the proteins will decide if the cell will divide and if so the cell goes to S phase (where the DNA is copied). |
g2 checkpoint | the proteins check to see if the DNA has been replicated properly and if so molecular processes begin |
mitosis checkpoint | if cells pass this point then the cell is done with mitosis and it goes through the cycle again |
synapsis | the pairing of homologous chromosomes |
tetrad | each pair of homologous chromosomes are called this |
crossing over | the process of chromatids breaking off and attaching to adjacent chromatids on the homologous chromosome. |
genetic recombination | when the cross over occurs and genetic material is shared by passing the new genetic material from generation to generation |
independent assortment | where homologous chromosomes randomly separate |
spermagenosis | the production of sperm cells |
oogenesis | the production of mature egg cells or ova |
polar bodies | the three products of meiosis |
sexual reproduction | the production of offspring by meiosis and the union of a sperm and an egg |