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57 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Robert Hooke |
used microscope to look at nonliving cork and observed the cork seemed to be made of tiny empty chambers he called "cells" |
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Anton van Leeuwenhoek |
examined pond water and a sample taken from a human mouth drew organisms he saw in the mouth - which we call bacteria today |
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Cells are the... |
Basic units of life |
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Schleiden |
concluded all plants were made of cells |
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Schwann |
concluded all animals were made of cells |
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Virchow |
concluded new cells were produced from existing cells |
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Cell theory (3) |
all living things are made of cells cells are basic units of structure/function in living things new cells are produced from existing cells |
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Light microscopes (4) |
- use light to pass through specimen - uses 2 lenses to form image - maximum magnification = 1,000 times - living and dead organisms observed |
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Why are dyes used to view living things under a microscope? |
because they are transparent and have distorted images and chemical stains/dyes fix that + freezes and kills the cell |
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Phase contrast microscope (3) |
type of light microscope increases differences in light and dark areas study living organisms and processes |
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How do microscopes work? |
use lenses to magnify the image of an object by focusing light or electrons |
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Electron microscopes (2) |
use beams of electrons that are focused by magnetic fields higher resolution that light microscopes |
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What are the two major types of electron microscopes? |
Transmission and Scanning |
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Transmission electron microscopes (TEM) (4) |
see cell structures and large proteins samples must be cut ultra thin to see inside produce flat 2D images examine only nonliving cells and tissues |
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Scanning electron microscopes (SEM) (4) |
see the surface of object NOT cut ultra thin produce 3D images of specimen's surface examine only nonliving cells & tissues |
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Prokaryotic cells (7) |
- cells that do NOT enclose DNA in nuclei - bacteria - found in extreme environments - earliest form of life -no organelles -circular DNA - smaller and simpler (size 1-10 micrometers) |
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Eukaryotic cells (7) |
- cells that enclose DNA in their nuclei - plants, animals, fungus, protists - have membrane enclosed organelles - later form of life - not found in extreme environments - linear DNA - larger and more complex (size 10-100 micrometers) |
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Similarities between prokaryotes and eukaryotes (5) |
- present today - have DNA - have cytoplasm - have cell membrane - exhibit all characteristics of life |
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Passive transport |
movement of materials across the cell membrane without using cellular energy |
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What are the 2 types of passive transport? |
Diffusion and Facilitated Diffusion |
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Diffusion (4) |
- particles move from high to low - move through lipid bilayer - without energy - until equilibrium |
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Facilitated Diffusion (5) |
- molecules can't directly diffuse across the lipid bilayer - moves through substance specific proteins - particles move from high to low - without energy - until equilibrium |
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Equilibrium |
reached when equal amounts of particles will continue to move across the membrane in both direction without change in net charge |
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Inside vs Outside of lipid bilayer |
inside = hydrophobic - water hating outside = hydrophilic - water loving |
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Aquaporins |
water channels in cells that allow water through |
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What would happen without aquaporins? |
water would diffuse very slowly |
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Osmosis (5) |
- facilitated diffusion - moves water through an aquaporin - from high to low concentration - without energy - until equilibrium |
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Active Transport |
movement of materials against a concentration gradient requiring energy to pump the materials through substance specific proteins |
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What are the 2 types of active transport? |
Molecular and Bulk transport |
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Molecular transport (3) |
- low to high concentration - through a protein - using energy |
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Bulk transport (2) |
Endocytosis and Exocytosis - movement of large substances |
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Endocytosis (4) |
energy releasing 1. Cell forms a pocket and molecules move in. 2. Smooth ER makes cell membrane to surround molecules. 3. Forms a vacuole (store) or vesicle (move) |
endo = into |
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Exocytosis (4) |
energy required 1. Vesicle from golgi fuses with cell membrane. 2. Cell membrane breaks down. 3. Molecules released from cell |
exo = out |
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What does ATP stand for? |
Adenosine triphosphate |
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Meaning of Isotonic solution |
the concentration of the solute outside the cell is the same as inside the cell |
iso = same |
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Effect on cell: Isotonic solution |
no change reached equilibrium continue to exchange particles equally |
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Meaning of Hypertonic solution |
Concentration of solute outside cell is higher than inside. solute IN solvent OUT |
hyper = high |
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Effect on cell: Hypertonic solution |
Cell shrinks because water molecules leave to dissolve the excess solute |
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In a hypertonic solution, do the water molecules move in, out, or stay the same? |
Out |
Higher |
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In a hypotonic solution, do the water molecules move in, out, or stay the same? |
In |
Lower |
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In an isotonic solution, do the water molecules move in, out, or stay the same? |
Stay the same |
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Meaning of Hypotonic solution |
Concentration of solute outside the cell is lower than inside the cell solute OUT solvent IN |
hypo = lower |
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Effect on cell: Hypotonic solution (3) |
Cell grows because water enters to dissolve the excess solute. Animal: too much water = it explodes Plant: water stored in central vacuole + cell wall prevents explosion |
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How do individual cells maintain homeostasis? |
grow, respond to environment, transform energy, and reproduce |
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How do cells of multicellular organisms work together to maintain homeostasis? |
become specialized for particular tasks (adapt) and communicate with one another |
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Levels of Organization |
specialized cells of multicellular organisms are organized into tissues, then into, organs, and into organ systems. creates a division of labor - maintains homeostasis |
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Tissue |
group of similar cells that performs a particular function |
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Organ |
tissues work together to complete complicated tasks |
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Organ system |
organs that work together to perform a function |
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Organelle |
membrane enclosed structure that is specialized to perform a specific function. |
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What kind of solution is this? |
Hypertonic |
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What kind of solution is this? |
Hypotonic |
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What kind of solution is this? |
Isotonic |
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What form of passive transport is this? |
Facilitated Diffusion |
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What form of passive transport is this? |
Diffusion |
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What form of buck transport is this? |
Endocytosis |
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What form of buck transport is this? (molecules starting in vesicle-moving out of cell) |
Exocytosis |
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