Principles Of Biology 1011 Lab 8 Flashcards

Front 1

Photosynethesis

Back 1

Photosynthesis is the process whereby plants or other organisms capture solar energy and store a portion of this as chemical energy. The plants themselves or organisms which eat them can then use this stored energy to carry out all of the varied processes required for the continuation of life. All life on earth depends on this or a very similar process. The plants store the captured energy in carbon compounds. The carbon itself comes from the atmosphere as carbon dioxide (CO2). The process of creating organic carbon compounds from atmospheric CO2 is referred to as carbon or CO2 fixation.

Lab 8

Front 2

Guard Cell

Back 2

Cell (the are in pairs) in a leaf which regulates the opening and closing of the stomata. Open to let in CO2, and closed to prevent water loss. Lab 8

Front 3

Stomata

Back 3

Or stoma. Openings in a leaf which allow carbon dioxide to enter. They are opened and closed by guard cells. Lab 8

Front 4

Chlorophyll

Back 4

Green pigment largely responsible for capturing solar energy for photosynthesis.

Lab 8

Front 5

Lower Epidermis

Back 5

Bottom layer of cells in a leaf, protects the leaf from damage. Lab 8

Front 6

Vascular Bundle

Back 6

The vascular system of the plant, which transports water, organic carbon, and minerals throughout the plant body. The cells are called the vascular bundle. Lab 8

Front 7

Chromatography

Back 7

Chromatography is the separation of pigments via differential movement in solvents as they wet a paper strip. Paper is composed of cellulose fiber pressed together to create a flat sheet. Recall that cellulose fibers come from plant cell walls. The cellulose fibers are absorbent and attract various solvents at different rates. As the solvent wets the paper, it carries upward any pigments that it has encountered and dissolved. Pigments that are large molecules or sticky (e. g., contain charged areas) tend to move more slowly; while those that are smaller or less sticky tend to move more rapidly. Lab 8

Front 8

Carbon Fixation

Back 8

The process of creating organic carbon compounds from atmospheric CO2 is referred to as carbon or CO2 fixation. The organic carbond compound may be a carbohydrate such as glucose, which is used for food.

Lab 8

Front 9

Cuticle

Back 9

This is a layer of waxes on a leaf is called the cuticle. It prevents water from evaporating directly out of plant epidermal cells, but also prevents diffusion of CO2 into the leaf. Lab 8

Front 10

Visible spectrum

Back 10

Range of radient energy that the human eye can see. Lab 8

Front 11

Wavelength

Back 11

Distance between successive wave crests. Different wavelengths of light have different colors.

Lab 8

Front 12

Plasmodesmata

Back 12

Plant cells are all interconnected by little tunnels called plasmodesmata, which connect the cytoplasm of adjacent cells. These tunnels allow free diffusion from cell to cell without the need to cross a plasma membrane.

Lab 8

Front 13

Upper epidermis

Back 13

Top layer of cells in a leaf, protects the leaf from damage. Lab 8

Front 14

Spongy Mesophyll

Back 14

This layer of the leaf is called the spongy mesophyll, and functions primarily in absorbing CO2. The spongy mesophyll must always present a cell wall surface moist with water so that CO2 can dissolve in it and move into the cells. Lab 8

Front 15

Absorption Spectrum

Back 15

The wavelengths of light absorbed by a pigment. Lab 8

Front 16

Palisade Mesophyll

Back 16

Directly below the upper epidermis of a leaf, you should see a layer of closely paced elongate cells. This is called the palisade mesophyll and these cells are active primarily in capturing light. Lab 8

Front 17

Spectrum

Back 17

Entire range of radiant energy.

Front 18

Fluorescence

Back 18

Light production accompanying the rapid decay of excited electrons returning to their ground state. Plants do this if they are incapable of doing photosynethesis. Lab 8