Bellringer-2/4/15

What is a cell? Recall your work yesterday. When

classifying cells, what are the two groups scientists separate cells into?

USING A MICROSCOPELight Microscopes and Total Power Magnification

Uses

We can use microscopes to observe cells in greater detail

Light microscopes are what we will use in class

More complicated microscopes, like scanning and electron transmission microscopes, allow us to see prokaryotic and eukaryotic cell differences in greater detail

Parts of a Light Microscope

Microscope: Total Power Magnification

To find this, multiply the power of the objective lens (4X, 10X, 40X), by the power of the eyepiece (usually 10X)

Example: A student is viewing a slide using an objective lens with a power of 4X. What is the total power magnification?

4 x 10 = 40X

CELLSStructure and Function of Living Organisms

What is a Cell?

A cell is the basic structural, functional, and biological unit of all living organisms “The building block of life”

You are made up of about 37 trillion cells!!!

Cell TheoryWhat do we know about cells?

Robert Hooke

▪ In 1665, Robert Hooke used an early microscope to look at a thin slice of cork, a plant material.

▪ Cork looked like thousands of tiny, empty chambers.

▪ Hooke called these chambers “cells.”

Hooke’s Original Sketches

History

▪ In 1838, Matthias Schleiden concluded that all plants were made of cells.

▪ In 1839, Theodor Schwann stated that all animals were made of cells.

▪ In 1855, Rudolph Virchow concluded that new cells were created only from division of existing cells.

▪ These discoveries led to the cell theory.

Cell Theory

1. All living things are composed of cells.

2. Cells are the basic units of structure and function in living things.

3. New cells are produced from existing cells.

Types of Cells

Prokaryotic Simple Cells

Eukaryotic Complex Cells Plant and Animal Cells

Prokaryotic Cells

Prokaryotic cells are less complex than eukaryotic cells No membrane

bound organelles; smaller

Single-celled organisms (ex. Bacteria)

Eukaryotic Cells

Eukaryotic cells are complex cells made up of membrane bound organelles

Each organelle within the cell carries out different roles

Eukaryotic cells make up complex organisms (mostly multicellular)…like insects, fish, and mammals like you!

Prokaryotic vs. EukaryoticPROKARYOTIC

No membrane bound organelles (no mitochondria, nucleus, vacuole, or chloroplasts)

Ribosomes DNA and RNA (not

enclosed) Circular DNA called

plasmids Smaller size

EUKARYOTIC

Contains membrane bound organelles

Ribosomes DNA and RNA

(enclosed by membrane)

DNA double-helix strands

Larger size

Bellringer-2/5/15

What is a cell? What does cell theory tell us about cells?

Fill in the chart comparing the two basic categories of cells.PROKARYOTIC EUKARYOTIC

Eukaryotic CellsAnimal vs. Plant

Animal Cell

•Nucleus•Plasma Membrane•Mitochondria•Vacuoles•Ribosome•Cytoplasm•Lysosome

Plant Cell

•Nucleus•Plasma Membrane•Mitochondria•Ribosome•Cytoplasm•Vacuole (large)•Chloroplasts•Cell Wall

What differences do you see right away?

Nucleus

The “control center”

Holds the DNA Dark spot inside

nucleus is called the nucleolus (it helps makes the ribosomes)

Nucleus

Mitochondria

The “powerhouse” of the cell

It produces most of the energy for the cell

Breaks down food to make ATP ATP is major fuel for all

cell activities that require energy

Folded inner membrane increase the surface area for energy production during respiration

Mitochondria

Plasma Membrane

The “gate” of the cell

Double membrane structure controls what comes in and out of the cell

“YOU SHALL NOT PASS”

Plasma Membrane

Ribosome

Protein producer The ribosome

makes proteins for the cell

Ribosome

Vacuole

“Storage tanks” of the cell

It stores food, water, and chemicals in the cell

Plant cell vacuole is much larger; controls Turgor Pressure-keeps plant upright (no water=wilting)

Vacuole

Vacuole in Plants

Cytoplasm

Jelly/gel A liquid/gel like

substance that surrounds the organelles

Cytoplasm

Lysosome (Animal Only)

The “garbage cans”

Break down and digest waste products using enzymes

Lysosome

Cell Wall (Plant Only)

“Supporter/protector”

The cell wall shapes and protects the plant cell

Cell Wall

Chloroplasts (Plant Only) Food producers They are green Contain green

chlorophyll and trap energy from the sun for photosynthesis

Chloroplast

Organelle Interactions

All these organelles work together to keep the cell running!!

What do you think would happen if… The Mitochondria or chloroplasts

stopped working? The Plasma Membrane didn’t do it’s job? The Nucleus stopped directing activities?

Summary: Plant vs. Animal Cells

Bellringer-2/6/15

1. How are prokaryotic and eukaryotic cells similar?

a) Both contain a nucleusb) Both contain ribosomesc) Both contain membrane-bound organellesd) Both contain cell walls

2. This diagram shows a plant cell. Which structure is found in a plant cell but absent in an animal cell?

a) 1b) 2c) 3d) 4

Review-Cell Organelles

Nucleus “Brain of the cell”-controls cell functions and

stores DNA Mitochondria

“Powerhouse of the cell”-makes energy through cellular respiration; folded inner membrane provides lots of surface area for cell processes

Cell membrane “Gate of the cell”-Double membrane structure

composed of lipids-controls what goes in and out

Review-Cell Organelles

Ribosomes Site of protein synthesis (makes

proteins); attached or free floating Cytoplasm

Gelly/jel that surrounds cells-keeps organelles where they should be

Vacuole “Storage center”-holds water, food, etc.-

large in plants due to Turgor Pressure

Review-Cell Organelles

Chloroplast Plants only-uses sunlight to convert to

sugar through process of photosynthesis Cell wall

Plants only-carbohydrate called cellulose provides rigid structure that protects and supports cell

Lysosome “Garbage can”-animals only. Uses

enzymes to digest waste products

Just a Note…Other Organelles

Endoplasmic Reticulum-Network of membranes that fold, modify, and transports proteins throughout the cell

Golgi Apparatus-receives proteins and lipids (fats); modifies, sorts, and packs them; works closely with the ER

Specialization of Cells

Cells all begin as undifferentiated-DNA and genetics play a role in determining the type of cell (ex. nerve cell, muscle, blood…)

We will talk more about this later!

Where would you need more…

Mitochondria? Chloroplasts?

Cell organelles can be more concentrated based on needs!

Lab Time!!!

Candy Cells

Bellringer-2/9/15

Decide whether the cell is plant or animal. Next, label the parts with the appropriate name.

Question of the Day

Which cellular process is most closely related the presence of chloroplasts in eukaryotes?a) Metabolismb) Photosynthesisc) Aerobic respirationd) Lactic acid fermentation

Cell Organelles

Sepuplhs.org/high/sgi/teachers/cell_sim.html

UNICELLULAR ORGANISMSStructure and Adaptations

Unicellular Organisms

A “multicellular” organism is composed of many cells (ex. You are composed of many animal cells; plants are composed of many plant cells)

“Unicellular” means they are composed of a single cell! Ex. Bacteria, protozoa, euglena

Structures of Unicellular Organisms

Unicellular organisms have many structures that help them survive Contractile vacuoles Cilia Flagella Psuedopods Eyespots

Contractile Vacuoles

Stores excess water that enters the cell, and expels it to the exterior It expands when filling

with water, then contracts, expelling the contents back out

Found in: protists + unicellular algae https://www.youtube.com/watch?

v=pahUt0RCKYc

Eyespots

A dark area that functions in light reception; influences motion so that the organism can move toward/ away from light Toward (positive phototaxis) Away (negative phototaxis) Found in: green algae;

photosynthetic unicellular organisms

Movement

Cilia Many hair like structures Often used for movement Non-motile cilia serve as

sensory organelles

Flagella Single, whip like tail used

for movement Found in: bacteria,

protists, specialized plant, animal and fungi cells

https://www.youtube.com/watch?v=QGAm6hMysTA

Movement

Psuedopods “False feet” that help the unicellular

organism move about Sometimes used to obtain food

(phagocytosis)

https://www.youtube.com/watch?v=PsYpngBG394

Adaptive Behaviors

Recall that “taxis” is an innate behavior in response to an outside stimuli

Chemotaxis

Movement in response to chemicals (“chemo”).

Some single celled organisms direct their movement according to chemicals in their environment

Found in bacteria and single-cell or multicellular organisms Find food (e.g., glucose) Flee from poisons (e.g., phenol) Critical to early development

Phototaxis

Movement toward or away from light. Many plant-like unicellular organisms

will move toward light to better photosynthesize, just like plants will tilt toward the window Positive phototaxis: if the movement is in

the direction of increasing light intensity Negative phototaxis: if the movement is

in the opposite direction of light intensity

https://www.youtube.com/watch?v=2koAGkgmiqg