Microscopy, Cells, and Diffusion and Osmosis test 1

Resolution

The ability of a microscope to distinguish two points as separate.

Contrast

The difference in light intensity between the image and the background.

Parcentered

When an object is in focus on one objective, it will remain centered when switching to another objective.

Parfocal

When an object is in focus on one objective, it will remain nearly in focus when switching to another objective.

Oculars

Eyepieces where you look through to see the image.

Arm

The part of the microscope you carry it by.

Fine Adjustment

Small focus knob for fine-tuning the image.

Coarse Adjustment

Larger focus knob for rough focusing.

Stage

Platform where the slide is placed.

Stage Clip

Clips used to hold the slide in place.

Stage Adjustment Knobs

Controls that move the stage for focusing.

Iris Diaphragm

Controls the amount of light passing through the specimen.

Condenser

Focuses light onto the specimen.

Light Source

Provides light for the specimen.

Nosepiece

Holds the objectives and allows you to rotate them into position.

Scanning Objective

4x magnification.

Low Power Objective

10x magnification.

High Power Objective

40x magnification (blue)

Oil Immersion Lens

100x magnification (requires oil).

Ocular Magnification

Usually 10x.

Objective Magnification

Identified by the label on each objective lens (4x, 10x, 40x, 100x).

Total Magnification

Multiply the ocular magnification by the objective magnification (e.g., 10x ocular and 40x objective = 400x total magnification).

Field of View

The area visible through the microscope.

Depth of Field

The thickness of the specimen that can be in focus.

Fixed Slides

Specimens are preserved and mounted on slides.

Wet Mount Slides

Specimens are placed in a drop of water and covered with a coverslip.

Plasma Membrane

Semi-permeable membrane that surrounds the cell.

Cytoplasm

Gel-like substance inside the cell where organelles are suspended.

DNA

Genetic material that carries information for cell function.

Prokaryotic Cells

Simple, no membrane-bound organelles, smaller. Includes bacteria.

Eukaryotic Cells

Complex, with membrane-bound organelles, larger. Includes plant and animal cells.

Cocci

Spherical shape of prokaryotes.

Bacilli

Rod-shaped prokaryotes.

Spirilla

Spiral shape of prokaryotes.

Cyanobacteria

Photosynthetic bacteria that play a key role in oxygen production and ecosystem balance.

Plasma Membrane

A cell part that surrounds the cell.

Cell Wall

A rigid outer layer found in plant cells.

Nucleoid Region

Area in prokaryotic cells where DNA is located.

Flagellum

A tail-like structure that helps in cell movement.

Plant Cells

Have cell walls, chloroplasts, and large central vacuoles.

Animal Cells

Lack cell walls and chloroplasts, have small vacuoles.

Chloroplasts

Contain chlorophyll for photosynthesis.

Amyloplasts

Store starch in plants.

Paramecium

Single-celled organism with cilia for movement.

Amoeba

Single-celled organism with pseudopodia (false feet) for movement.

Brownian Movement

Random movement of particles due to thermal energy.

Diffusion

Movement of molecules from high concentration to low concentration.

Osmosis

Diffusion of water across a semi-permeable membrane.

Hypertonic

Solution has a higher concentration of solutes than the cell (cell will lose water).

Hypotonic

Solution has a lower concentration of solutes than the cell (cell will gain water).

Isotonic

Solution has the same concentration of solutes as the cell (no net movement of water).

Solute

The substance being dissolved.

Solvent

The substance that does the dissolving (usually water).

Plasmolysis

Shrinking of plant cell membrane due to water loss in a hypertonic environment.

Turgor Pressure

Pressure exerted by the central vacuole in plant cells to maintain structure and prevent wilting.

Tonicity

Hypertonic-higher solutes

Isotonic-equal solutes

Hypotonic-lower solutes

Cytobaterica

has photosynthesis

smaller

______ molecules more faster

(final mass -initial mass)(divided by initial mass) x100

formula for percentage change

Nucleus

Membrane bound organelle where DNA is located in eukaryotes ; area where most of the genetic material is organized and expressed

Chromatin

A complex of protein and DNA found in the nucleus

Nucleolus

Site within the nucleus were ribosome subunit assembly occurs ; ribosomes are made here .

Rough Endoplasmic reticulum

Folded membranes embedded with ribosomes ; site of protein sorting and secretion .

Smooth Endoplasmic reticulum

Folded membranes without ribosomes ; site of detoxification and lipid synthesis .

Golgi apparatus

Site of modification , sorting , and secretion of proteins and lipids ; the post office of the cell

Lysosomes

Site where macromolecules are degraded

Membrane - phospholipid bilayer

Membrane that controls movement of substances into and out of the cell ; site of cell signaling

Mitochondria

Site of ATP synthesis ,

Plastids - chloroplast

Site of photosynthesis in plants only

Plastids amyloplasts

Plastids that store starch in plants only

Plastids- chromoplasts

Plastids that store and synthesize pigments that give color to fruits , flowers , and vegetables ( plants only ) that provides cell never

Cell walls

plants , and fungi ; never present in animal cells Structure that provides cell support in bacteria ,

Storage vacuole

An organelle in plant cells that stores proteins , nutrients , and other compounds

Central vacuole

Site that provides storage and regulation of cell volume ; maintains turgor pressure