Comprehensive Review (plus Unit #4 terms) Flashcards
Cleavage
Cell division without growth (in animals)
Blastula
In vertebrates, an early embryonic stage consisting of a hollow, fluid-filled ball of cells one layer thick; a vertebrate embryo after cleavage and before gastrulation.
Gastrula
In vertebrates, the embryonic stage in which the blastula with its single layer of cells turns into a three-layered embryo mads up of ectoderm, endoderm, and mesoderm.
Zygote
A diploid cell
Morula
Solid ball of cells in the early stage of an organism.
Endoderm
One of three embryonic germ layers of early vertebrate embryos, that later line internal structures such as digestive and respiratory tracts.
Ectoderm
One of three embryonic germ layers of early vertebrate embryos, gives rise to outer layers of body (skin, hair, nails), and nerve tissue.
Mesoderm
One of three embryonic germ layers of early vertebrate embryos, gives rise to inner tissues like muscles, blood, bone, etc.
Blastomere
One of the cells of the blastula
Nurse cells
Help an egg grow before fertilization (like insect) by moving some of their own maternally encoded mRNA into the cytoplasm of the oocyte (maturing egg).
Syncytium
A single cytoplasm with ~4000 nuclei in embryonic development of insects like Drosophila.
Imaginal disks
One of about a dozen groups of cells set aside in the abdomen of a larval insect and committed to forming key parts of the insect’s body
Instars
A larval development of insects
Pupae
Developmental stage of some insects in which the organism is nonfeeding, immobile, and sometimes encapsulated in a cocoon. Between larval and adult stages.
Meristem
Undifferentiated plant tissue from which new cells arise.
Cotyledon
A seed leaf that generally stores food, providing nourishment during seed germination.
Pluripotent
Cells that are capable of becoming many things (but are limited in scope)
Induction
- Binding of an inducer to a repressor allows transcription of an operon.
- In embryonic development, when development of a cell is influenced by interaction with an adjacent cell.
Totipotent
A cell that can become anything else in an organism (blastomeres).
Homeotic
Series of “master switch” genes that determine the form of segments developing in the embryo.
Segmentation mutant
Give segmentation problems (like 2-legs per section which became millipedes).
Homeobox
A sequence of 180 nucleotides located in homeotic genes that produces a 60-amino-acid peptide sequence active in transcription factors.
Apoptosis
A process of programmed cell death, in which dying cells shrivel and shrink; used in animal cell development to produce planned and orderly elimination of cells not intended for the final tissue.
C. elegans
A nematode worm with 959 somatic cells. One of most completely described models of development.
Blastocyst
Mammal egg initial division results in a lingle layer of cells surrounding a fluid-filled center.
Inner cell mass
Inside the blastula. Becomes the embryo with endoderm, mesoderm, and ectoderm.
Trophoblast
In vertebrate embryos, the outer ectodermal layer of the blastodermic vesicle. Becomes the placenta.
Oncogene
A mutant form of a growth-regulating gene that is inappropriately “on”, causing unrestrained cell growth and division.
Protein
Polymers of amino acids. (shape and specific order of amino acid monomers determines the structure and function)
Functions:
* enzyme catalysts
* defense (anti-bodies)
* transport (iron in living things, bind O)
* support (can be structural, connective tissue, ligaments)
* motion (muscles contracting)
* regulation (turn on/off other processes)
* storage (of amino acids)
RNA
- Ribonucleic acid, single-stranded.
- Nitrogenous bases consist of adenine, guanine, uracil, and cytosine.
- Mostly for info retrieval (broken down). Reads DNA for protein construction (directs their synthesis) and genetic information.
DNA
- Deoxyribonucleic acid
- double-stranded in a double helix, connected by H bonds.
- Nitrogenous bases consist of adenine, guanine, thymine, and cytosine.
- Mostly for information storage (built up). Read to build proteins. Also, genetic information stored in the sequence of nucleotides.
Lipid
- Fats (triglycerides) and phospholipids
- Hydrophobic (caused by high proportion of C-H bonds)
- symmetrical
Glycogen
A polymer of glucose monosaccharides for energy storage in animals. Stored in a branching structure (like a bush) to quickly store or release sugar molecules.
Amino Acid
- Monomer that composes the polymers that are proteins.
- There are 20 different kinds.
- Joined by peptide bonds (covalent)
- Structure: a central C bonded to one amino group, one carboxyl group, one H, and an R group (which determines the unique character of the 20 different amino acids).
Fatty acid
Long hydrocarbon chains that can be saturated, unsaturated, or polyunsaturated.
Nucleotide
A single unit of nucleic acid, composed of a phosphate, a five-carbon sugar (ribose or deoxyribose), and a purine or a pyrimidine.
Nucleus
- In atoms, the center of an atom, with protons and neutrons
- In eukaryotic cells, the organelle that houses the DNA
- Site of gene transcription.
Mitochondrion
- The “power house” of the cell - generates ATP.
- Contains its own DNA.
- -surrounded by 2 membranes:
- smooth outer membrane
- folded inner membrane with layers (called cristae)
Lysosome
- The “trash can” of the cell.
- membrane bound vesicles containing digestive enzymes to break down macromolecules
- destroy cells or foreign matter that the cell has engulfed (by phagocytosis)
Golgi Apparatus
- The “shipping and receiving” department of the cell.
- flattened stacks of interconnected membranes
- packaging and distribution of materials to different parts of the cell
- synthesis of cell wall components
Endoplasmic Reticulum
- Functions: Synthesize proteins and fats, detoxify foreign substances, store calcium
- Composition: phospholipid bilayer embedded with proteins
Glycolysis (definition/description)
- The break-down of glucose in a cell for metabolism
- E- of C-H bonds are stripped off in a series of reactions
- Occurs in the cytoplasm
- Results in net gain of 2 ATP
Krebs cycle (definition)
- 9-step process to reduce the acetyl group from Pyruvate Oxidation
- Occurs in the matrix of the mitochondria
- Otherwise known as the citric acid cycle or TCA cycle
- When the cell’s ATP concentration is high, the process shuts down and acetyl-CoA is channeled into fat synthesis.
Electron Transport Chain
- Series of e- carriers to store energy from oxidation reactions
- Located in the inner membrane of the mitochondrion.
- Electrons from NADH and FADH2 are transferred from complex to complex, with some e- energy lost at each transfer, used to pump H+ out of matrix to inter-membrane space.
Lactic Acid Fermentation
- rids body of pyruvate
Muscle cells convert pyruvate into lactic acid (lactate is ionized form). An excess of production contributes to muscle fatigue.
Alcoholic Fermentation
Glycolysis produces pyruvate which CO2 is stripped from (a by-product) and converted to acetaldehyde which becomes ethanol.
Chemiosmosis
see ATP synthase
ATP Synthase
- An enzyme that facilitates the synthesis of ATP through oxidative phosphorylation (a second method to substrate-level - energy to transfer the phosphate comes from a proton gradient).
- A membrane-bound enzyme that uses the energy of the proton gradient to synthesize ATP from ADP + Pi
- 1 proton results in 1 ATP
- process is called chemiosmosis
Proton Pump
see ATP synthase
NADH dehydrogenase
- the first membrane-embedded enzyme to receive e- in the e- transport chain
- oxidizes NADH to NAD+ and releases a proton (H+) to the intermembrane space
Cytochrome b-c complex
- bc complex is the second enzyme in the e- transport chain which uses energy from e- to pump a proton to the intermembrane space
- cytochrome oxidase complex does the same thing, pumping another proton
Calvin Cycle
- also called light-independent reactions (of photosynthesis) and carbon fixation reactions
- If O2 is available, uses ATP and NADPH to synthesize organic molecules from CO2
- If O2 is not available, side reactions store (?) as oxyloacetate when plant stomata are closed (C4 plants)
G3P
Intermediate product of glycolysis and end product of the Calvin Cycle
Acetyl-CoA
- The end product of Pyruvate Oxidation
- consists of 2 carbons from pyruvate attached to coenzyme A
- Reacts with oxyloacetate to start the Krebs Cycle
- When the cell’s ATP concentration is high, the process
shuts down and acetyl-CoA is channeled into fat
Oxaloacetic Acid
- “Feeder” molecule (4-carbon) that reacts with acetyl-CoA to start the Krebs Cycle
- Also the Step 9 product of the Krebs Cycle