Matter in Living Systems

Flashcards covering vocabulary related to matter in living systems, including cell theory, imaging technologies, cell structures, transport mechanisms, and plant control systems.

Hans and Zacharias Janssen

Developed the first compound microscope with a 2-lens system.

Robert Hooke

Improved microscope design by adding a third lens and a light; observed 'cells' in cork.

Antoni van Leeuwenhoek

Developed a simple microscope that could magnify up to 250X; observed living cells and called them 'animalcules'.

Spontaneous generation (abiogenesis)

The idea that life emerges spontaneously from non-living matter.

Francesco Redi's experiment

Experiment showed that flies were needed for maggots to appear on meat, disproving spontaneous generation.

John Needham

Concluded that microorganisms appeared in boiled broth due to a life force.

Lazzaro Spallanzani

Repeated Needham's experiment in a vacuum and showed no microorganisms appeared, but still believed air was the life force ingredient.

Louis Pasteur

Experiments proved biogenesis; organisms arise from other organisms.

Robert Brown

Observed nuclei in orchid cells using a single-lens microscope.

M.J. Schleiden

Observed that all plants are composed of cells containing a nucleus.

Schleiden and Schwann

Proposed that all plants and animals are composed of cells and that the cell is the basic unit of all organisms.

Rudolph Virchow

Theorized that all cells arise only from pre-existing cells.

Cell Theory

States that all living things are made of cells, all life functions occur in cells, and all cells come from pre-existing cells.

Magnification

Increasing the size of the image produced by a microscope.

Contrast

Ability to distinguish between structures in the cell when using a microscope.

Resolution

Shortest distance between two points on a specimen that can still be distinguished as separate points.

Electron Microscopes

Microscopes that use electrons instead of light to visualize specimens; have higher resolution and magnification.

Micrographs

Photographs taken through electron microscopes.

Transmission Electron Microscope (TEM)

Provides information about the inner structure of a specimen.

Scanning Electron Microscope (SEM)

Provides information about the surface of specimens.

Confocal Laser Scanning Microscopes

Microscopes that use a laser beam to view living cells in three dimensions.

Eyepiece/Ocular Lens

Lens that the observer looks through.

Stage Clips

Hold the slide in place on the stage.

Coarse Adjustment Knob

Moves the stage up and down to adjust focus.

Fine Adjustment Knob

Adjusts fine focus.

Objective Lenses

Lenses nearest the specimen being viewed (low, medium, high power).

Diaphragm

Controls the amount of light passing through the specimen.

Revolving Nosepiece

Where the objective lenses are mounted; rotates to select the lens.

Stage

Flat piece where you place the slide to view.

Aperture

Adjustable disk under the stage that controls how much light passes through.

Total Magnification

Calculated by multiplying the magnification of the ocular lens by the magnification of the objective lens.

Gene Mapping

Studying the molecular structure of DNA and mapping the genomes of various species.

Cell Communication

Using green fluorescent protein technology to observe molecules involved in communication between cells.

X-ray Crystallography

Studying the 3-D shape of normally functioning and defective proteins.

System

A set of interconnected parts.

Open system

Exchanges both matter and energy with its surroundings.

Cell membrane

a protective barrier for the cell

Cell Wall

rigid frame around the cell that provides strength and support

Cytoplasm

gel-like substance inside the cell membrane

Cytoskeleton

filaments inside the cytoplasm that act as a framework

Nucleus

contains DNA, the genetic material of the cell that directs all cellular activities

Lysosomes

membrane-bound sacs containing strong chemicals that break down and recycle materials

Vacuoles

membrane-bound storage site for water

Vesicles

membrane-bound sites for the storage and transport of nutrients

Mitochondria

Site of cellular respiration

Chloroplasts

Contain a green pigment called chlorophyll

Ribosomes

Site of protein synthesis

Endoplasmic Reticulum

Series of tubes extending from the nuclear envelope

Golgi Apparatus

Flat disc-shaped sacs involved in modifying and packaging substances

Cell Membrane

Semi-permeable membrane that helps maintain homeostasis within the cell.

Glycoproteins

Proteins with sugar attached; used for cellular communication and identification.

Fluid Mosaic Model

Model for cell membrane structure; membrane is flexible and components can move throughout.

Particle Model of Matter

States that all matter is made up of particles in constant motion.

Concentration

Amount of a solute dissolved in a specific volume of solvent.

Concentration Gradient

Relative difference in concentration of a substance between two areas.

Diffusion

Net movement of particles from an area of higher concentration to an area of lower concentration.

Osmosis

Diffusion of water across a membrane.

Hypertonic

Environment where the concentration of solute is greater outside the cell than inside.

Hypotonic

Environment where the concentration of solute is less outside the cell than inside.

Isotonic

Environment where the concentration of solute is equal inside and outside the cell.

Plasmolysis

Cell membrane and contents pull away from the cell wall.

Deplasmolysis

Plant becomes turgid and stands upright.

Facilitated Diffusion

Uses transport proteins to move large or charged particles across the cell membrane.

Channel Proteins

Provide a water-filled passage for ions and other water-soluble substances to move through.

Carrier Proteins

Bind to larger solutes and changes shape to release the solute into the cell.

Active Transport

Transport of materials across the membrane using protein pumps; requires ATP.

Endocytosis

Part of the cell membrane folds around the substance, creating a vesicle, and bringing it into the cell.

Exocytosis

Membrane vesicle fuses with the cell membrane and releases its contents outside of the cell.

Liposomes

Artificial cell membranes used to deliver medications to specific cells through endocytosis.

Transdermal patches

System by which medications are delivered through diffusion through the skin.

Reverse osmosis

Water is filtered by forcing it through an artificial membrane against the concentration gradient.

Kidney dialysis

Filtering of waste products from the blood using a semi-permeable membrane.

Surface Area

Total area of the outside of the cell membrane.

Volume

Volume of the contents of the cell.

Shoot system

Everything that is above the ground; includes the stem, leaves, buds, flowers, fruit and tubers.

Root system

Everything that is below the ground except tubers; includes roots as well as aerial roots above ground.

Dermal Tissue

Outer layer of cells that covers all herbaceous plants.

Ground Tissue

Makes up the majority of the plant and is found as a layer beneath the epidermis.

Xylem

Moves water and minerals from the roots to the shoots of the plant.

Phloem

Transports dissolved sugars made during photosynthesis from the shoots to the roots of the plant.

Stomata

Tiny openings in the leaf that allow for the diffusion of CO2 and O2 as well as transpiration.

Guard Cells

Regulate the opening and closing of the stomata.

Turgor Pressure

Force inside the plant cell that pushes the plasma membrane against the cell wall

Lenticels

Pores along the stems of woody plants where gas exchange and transpiration occur.

Mesophyll

The ground tissue of the leaf.

Palisade Tissue

Tightly packed cells in the mesophyll that contain many chloroplasts for photosynthesis.

Spongy Mesophyll Tissue

Loosely packed cells in the mesophyll that allow space for gases to diffuse through the leaf

Pit Membrane

Specialized membrane between adjacent cell walls in xylem vessels.

Cohesion

Tendency for water molecules to stick together.

Adhesion

Tendency of water molecules to stick to certain surfaces.

Gravitropism

Growth in response to the force of gravity.

Phototropism

Growth in response to light.

Auxin

Hormone produced in the tip of plants that promotes cell elongation.

Thigmotropism

Growth in response to touch.

Hydrotropism

Growth of roots towards water.

Photoperiodism

Growth in response to light availability.