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30 Cards in this Set
- Front
- Back
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nutrition
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– process by which nutrients are acquired from the environment and used for cellular activities
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essential nutrients
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- must be provided to an organism
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Two categories of essential nutrients
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macronutrients and micronutrients or trace elements
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macronutrients
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required in large quantities; play principal roles in cell structure and metabolism – Proteins and sugars
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micronutrients or trace elements
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required in small amounts; involved in enzyme function and maintenance of protein structure. Zinc and manganese
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Inorganic nutrients
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atom or molecule that contains a combination of atoms other than carbon and hydrogen
metals and their salts (magnesium sulfate, ferric nitrate, sodium phosphate), gases (oxygen, carbon dioxide) and water |
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Organic nutrients
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contain carbon and hydrogen atoms and are usually the products of living things
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Heterotroph
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must obtain carbon in an organic form made by other living organisms such as proteins, carbohydrates, lipids and nucleic acids
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Autotroph
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an organism that uses CO2, an inorganic gas as its carbon source-- not nutritionally dependent on other living things
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Nitrogen facts
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1. Nitrogen is part of the structure of proteins, DNA, RNA & ATP .
2. Some bacteria & algae use inorganic N nutrients (NO3-, NO2-, or NH3). 3. Some bacteria can fix N2. 4. Regardless of how N enters the cell, it must be converted to NH3. |
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Hydrogen Sources
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Major element in all organic compounds and several inorganic ones (water, salts and gases)
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Roles of hydrogen
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serving as the source of free energy in oxidation-reduction reactions of respiration
maintaining pH |
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Phosphorous (Phosphate Sources)
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Main inorganic source is phosphate (PO4-3) derived from phosphoric acid (H3PO4) found in rocks and oceanic mineral deposits
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Roles of Phosphorous
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Key component of nucleic acids, essential to genetics
Serves in energy transfers (ATP) |
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Sulfur Sources
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Essential component of some vitamins and the amino acids: methionine and cysteine
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Role of Sulfer
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Contributes to stability of proteins by forming disulfide bonds
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chemotroph
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gain energy from chemical compounds
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phototrophs
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gain energy through photosynthesis
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saprobe
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Metabolize the organic matter of dead organisms
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Parasite
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using the tissue and fluids of a live host
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Passive transport
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does not require energy; substances move from areas of higher concentration towards areas of lower concentration
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Three types of Passive transport
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diffusion
osmosis – diffusion of water facilitated diffusion – requires a carrier |
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Active transport
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requires energy and carrier proteins; gradient independent
active transport |
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Two types of Active transport
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group translocation – transported molecule chemically altered
bulk transport – endocytosis, exocytosis, pinocytosis |
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Osmosis
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diffusion of water from area of higher concentration to area of lower concentration
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Diffusion
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movement of molecules from areas of higher concentration to areas of lower concentration.
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Facilitated Diffusion
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movement of molecules from areas of higher concentration to areas of lower concentration.
requires no energy requires a special protein carrier in the membrane |
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Osmosis
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movement of water molecules across a membrane from areas of higher concentration to areas of lower concentration
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Isotonic
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water concentration is equal both inside and outside the cell
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Hypertonic
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water concentration is lower inside the cell and higher outside the cell;
water diffuses out of the cell causing cretnate the solution has a higher concentration of solutes |
