Term
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Definition
1. All organisms are composed of one or more cells. Metabolism and heredity occur in those cells.
2. Cells are the smallest living things, basic units of all organisms.
3. Cells arise only by division of previously existing cells. |
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Term
| What is the impact of cell size on cell functioning? What is the range of known cell sizes? |
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Definition
1. Small cells have more surface area per unit of volume than large. As a cell size increases, its volume increases more rapidly than its surface area.
2. Most cells are less than 50µm in diameter. |
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Term
| What structures do all cells have? |
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Definition
| 1. They all have four features: nucleoid or nucleus (DNA in there), cytoplasm, ribosomes to synthesize proteins, a plasma membrane. |
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Term
| How do prokaryotic and eukaryotic cells differ from each other? |
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Definition
1. Prokaryotes are the simplest organisms. Most of their genetic material lies in a single monecule of DNA which is near the center of the cell in a nucleoid.
2. Eukaryotes have DNA in the nucleus surrounded by a double membrane structure called the nuclear envelope.
Both have the DNA and genes that code for proteins synthesized by the cell. |
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Term
| What are some of the key structures found in prokaryotic cells? What are the functions of these structures? |
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Definition
1. Cytoplasm surrounded by a plasma membrane encased with a rigid cell wall. These prokaryotic cells have no distinct interior compartments.
2. Cytoplasm – fills interior of the cell and contains sugar, amino acids and proteins that the cell needs to carry out everyday activities. |
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Term
| What is the impact of compartmentalization on eukaryotic cells? How do eukaryotes achieve compartmentalization? |
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Definition
| 1. In eukaryotic cells the cytoplasm contains membrane bound compartments called organelles. These organelles do different things in the cell. |
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Term
| What is the structure and function of the eukaryotic nucleus and nucleolus? |
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Definition
| The nucleus leads to the synthesis of all the proteins of a eukaryotic cell. It’s in the central region of the cell, network of fine cytoplasm filaments. |
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Term
| What are the components of the endomembrane system? What are the functions of these different components? |
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Definition
| It fills the cell dividing it into compartments channeling the passage of molecules through the interior of the cell and providing surfaces for the synthesis of lipids and some proteins. |
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Term
| What type of cells contains glyoxysomes, peroxisomes, and vacuoles and what are their major functions in these cells? |
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Definition
1. Gloxysomes are a special type of microbody in plants. Contains enzymes that convert fat in carbohydrates.
2. Peroxisomes contain enzymes that catalyst the removal of electrons and associated hydrogen atoms. Spherical shape organelle containing a large crystal structure composed of proteins and digestive and detoxifying enzymes. They produce hydrogen peroxide as a byproduct.
3. Vacuoles are specialized membrane bound structures. It stores dissolved substances and it can expand in size to increase the toxicity of a plant cell. |
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Term
| What is the probable source of chloroplasts and mitochondria in eukaryotic cells? What are their functions? |
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Definition
1. The inner membrane of the chloroplast surrounds a membrane system of stacks of closed chlorophyll containing vesticles called thylakoids. Photosynthesis takes place within them.
2. Mitochondria are tubular shaped organelles. They are bounded by 2 membranes- smoother outer membrane and inner folded membrane. They have their own DNA. They are involved in energy metabolism, they make ATP. It carries out oxidative metabolism. |
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Term
| What is the structure and function of the different cytoskeleton components? |
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Definition
1. Actin filaments (microfilaments) – 2 protein chains twined together like 2 strands of pearls. They are responsible for cellular movement, contraction, crawling, pinching, during the formation of cellular divison.
2. Microtubules – composed of a ring of 13 protein protofilaments. They are responsible for moving materials within the cell itself.
3. Intermediate filaments – the most durable, they are fiberous protein molecules twined together. They are provide structural stability for cells. |
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Term
| What extracellular structures are found in plant and animal cells? What functions do they serve? |
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Definition
1. Animal cells are surrounded by an extracellular matrix composed of various glycoproteins that give the cells support, strength, and resilience. They are formed by glycoproteins.
2. Plant cells have a cellulose base cell wall. |
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Term
| What are the major events in the history of life on Earth? What were the consequences of these events? |
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Definition
1. Earth formed and cooled which made water vapor in the atmosphere which made the ocean. Life originated in the ocean.
2. Life began when organic molecules assembled in a coordinated manner within a cell membrane and began reproducing. |
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Term
| How did the first cells probably originate? |
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Definition
| Cells evolved from the functional assembly of organic molecules. Had a metabolic reaction |
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Term
| what are the two primary, scientific hypotheses regarding the origin of life on Earth? What evidence is there for each? |
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Definition
1. Life may have infected earth from another planet – Panspermia - Meteors or cosmic dust may have carried complex organic molecules to earth.
2. They think that early earth because it was so hot gave birth to life. |
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Term
| What is the RNA world? What evidence is there for it? |
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Definition
| The RNA world hypothesis is a theory which proposes that a world filled with RNA (ribonucleic acid) based life predates current DNA (deoxyribonucleic acid) based life. This is thought because RNA can act like an enzyme while DNA can’t. |
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Term
| What are the major components of cellular membranes, what are their properties, and what functions do they serve? |
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Definition
There are four components.
1. Phospholipid bilayer- provides a flexible matrix but also a barrier to permeability
2. Transmembrane proteins – collection of proteins that float in the lipid bilayer called integral membrane proteins
3. Interior protein network – structurally supported by intracellular proteins that reinforce the membranes shape. 4. Cell surface markers – adds chains of sugar molecules to membrane proteins and lipids. |
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