Cells

Cell The basic unit of life

Cell Theory All living things are made of cells Unicellular – 1 cell (ex. Bacteria) Multicellular – 2+ cells (ex. Animals, plants) multicellular- 2+ cells unicellular- 1 cell

Beginning unit is always a CELL! Cell Theory The cell is the basic unit of life Beginning unit is always a CELL! cells organs organism tissues Organ system

Cell Theory All cells come from pre-existing cells. muscle muscle

Cell Theory Viruses are exceptions to the Cell Theory They are not alive, yet they are able to reproduce using cells!

Robert Hooke 1665 He used a compound light microscope to observe cork cells. He was the first to use the term “cell” in biology.

Cell Discovery: We can look at cells with a: Microscope!

Total Magnification Found by magnifying the eye piece by the objective. 1.) On our microscopes, the objective is 4x and the eyepiece is 10x. What is the Total Magnification? 2.) What is the total magnification if the eyepiece is 10x and the objective is 10x?

How to use a microscope: 1.) Use the lowest power objective first (4x) 2.) Use the coarse adjustment knob to view the slide at the lowest power objective. 3.) Then use the fine adjustment knob to focus the slide at the lowest power objective. 4.) Once focused, turn to the next highest objective. Only use the fine adjustment knob to focus it.

The Electron Microscope Developed in the 1940s Uses a beam of electrons instead of light. 500,000x magnification Allows viewing of structures located inside of cell.

Bellwork: Write the date! What are the three parts of the cell theory? Who is Robert Hooke? How do you find the total magnification of a microscope? Contrast a light microsope and an electron microscope. When would you use the coarse adjustment know? The fine adjustment knob?

Bio. 1.1 Understand the relationship between the structures and functions of cells and their organelles Bio 1.1.2 Compare prokaryotic and eukaryotic cells in terms of their general structures (plasma membrane and genetic material) and degree of complexity Unpacked: •Proficiently use proper light microscopic techniques as well as determine total power magnification. The purpose is to use microscopes to observe a variety of cells with particular emphasis on the differences between prokaryotic and eukaryotic as well as plant and animal cells. While students are not expected to understand how scanning and electron transmission microscopes work, they should recognize that they reveal greater detail about eukaryotic and prokaryotic cell differences. • Infer that prokaryotic cells are less complex than eukaryotic cells. • Compare the structure of prokaryotic and eukaryotic cells to conclude the following: Presence of membrane bound organelles – mitochondria, nucleus, vacuole, and chloroplasts are not present in prokaryotes. Ribosomes are found in both. DNA and RNA are present in both, but are not enclosed by a membrane in prokaryotes. Contrasts in chromosome structure – circular DNA strands called plasmids are characteristic of prokaryotes. Contrasts in size – prokaryotic cells are smaller.  

Two Types of Cells Prokaryotic Cell Ex. Bacteria Eukaryotic Cell – Ex. Plant and Animal

Prokaryotic Cells NO nucleus Simple, small DNA (plasmid) & RNA (circular DNA) No membrane bound organelles Ribosomes Example: Bacteria

2. DNA 3. Plasma membrane 1. Ribosomes 4. Cell wall A prokaryotic cell does not have internal organelles surrounded by a membrane. Most of a prokaryote’s metabolism takes place in the cytoplasm. 2. DNA 3. Plasma membrane 1. Ribosomes 4. Cell wall Chapter Assessment

Eukaryotic Cells Have a Nucleus Complex, bigger Membrane bound organelles DNA in chromosome form Ribosome Some unicellular (algae) Example: Plant, animal cells

1. Nucleus 2. Chromosomes (DNA) 3. Plasma membrane 4. Organelles This eukaryotic cell from an animal has distinct membrane-bound organelles that allow different parts of the cell to perform different functions. 1. Nucleus 2. Chromosomes (DNA) Heredity material 3. Plasma membrane 4. Organelles Chapter Assessment

Prokaryotes vs eukaryotes Simple DNA and RNA, but not surrounded by membrane bound nucleus Circular DNA called plasmid NO organelles Ribosomes Small Complex DNA and RNA in nucleus DNA in chromosome structure Organelles Ribosomes Large

Bio. 1.1 Understand the relationship between the structures and functions of cells and their organelles Bio. 1.1.1 Summarize the structure and function of organelles in eukaryotic cells (including the nucleus, plasma membrane, cell wall, mitochondria, vacuoles, chloroplasts, and ribosomes) and ways that these organelles interact with each other to perform the function of the cell Unpacked: •Identify these cell organelles in diagrams of plant and animal cells. • Explain how the structure of the organelle determines it function. (Example: folded inner membrane in mitochondria increases surface area for energy production during aerobic cellular respiration). • Summarize how these organelles interact to carry out functions such as energy production and use, transport of molecules, disposal of waste, and synthesis of new molecules. (Example: DNA codes for proteins which are assembled by the ribosomes and used as enzymes for energy production at the mitochondria).  

Cell Parts

Cell Parts DNA – genetic info. ALL CELLS

Cell Parts Cytoplasm Fluid part of the cell Makes up most of cell Organelles found in cytoplasm Most life processes take place in cytoplasm

Cell Parts Plasma Membrane – maintains homeostasis by letting certain things in while keeping others out. ALL CELLS

Cell Parts Organelles

Organelles Small structures in cytoplasm with special jobs - keep cell working properly Structure determines function: Folded membranes increase surface area improve efficiency Interact together to perform certain functions Energy production and use Synthesis new molecules

Organelles Nucleus – controls all cell function (holds the DNA)!!! EUKARYOTES ONLY

Organelles Ribosomes – make proteins. ALL CELLS Some are free floating and some attached to ER

Ribosomes attached to ER (endoplasmic reticulum).

Organelles Endoplasmic reticulum – synthesis of new molecules. Has ribosomes attached.

Organelles Mitochondria – makes energy (powerhouse) Breaks down glucose to make ATP Double membraned EUKARYOTES ONLY

Mitochondria Extras Provides much of the energy for processes in living organisms such as: Muscle contractions in earthworms Storage of calcium ions Aid in metabolism

Organelles Vacuole – stores food and water EUKARYOTES ONLY

Vacuoles Plant or animal cell? Many small vacuoles in animal cells One or two large vacuoles in plant cells http://sciencecity.oupchina.com.hk/biology/student/glossary/img/vacuole.jpg 2/17/06

Plant Cell Vacuole Animal Cell

Organelles Golgi Body – packages and sorts proteins EUKARYOTES ONLY!

Organelles Chloroplasts – make food for plant cells PLANT CELLS ONLY

Chloroplasts Contain chlorophyll (reflect green light) Site of Photosynthesis (makes glucose) Found in plants and other autotrophs

Notice Green color! 

Organelles Cell Wall – hard protection and support, structure Surrounds cell Made of cellulose PLANT CELLS ONLY

Plasma or Cell Membrane Outside of cell Inside of cell Cell Wall Plasma or Cell Membrane Cell wall is always located outside of plasma membrane.

Organelles Centrioles - aid in mitosis ANIMAL CELLS ONLY!!

Organelles Lysosomes - digests waste for cell EUKARYOTES ONLY

Organelles How do organelles interact?

Organelles Can you name the organelle???

What are these organelles? What is their function?

What are these organelles? ribosomes What is their function? To make proteins

What is this organelle? What is the green material inside the chloroplast? What is its function?

What is the green material inside the chloroplast? What is this organelle? Chloroplast What is the green material inside the chloroplast? chlorophyll What is its function? photosynthesis

What is this organelle? What does this organelle make for the cell? What is the process called by which the mitochondria make cellular energy (ATP)?

What does this organelle make for the cell? What is this organelle? Mitochondrion What does this organelle make for the cell? energy What is the process called by which the mitochondria make cellular energy (ATP)? respiration

What is this organelle? What important material is stored inside the nucleus? What is the outer covering around the nucleus called?

What important material is stored inside the nucleus? What is this organelle? nucleus What important material is stored inside the nucleus? DNA (DNA coils to make chromosomes) What is the outer covering around the nucleus called? Nuclear membrane

What organelle is the arrow pointing to? What is the function of the vacuole? What is stored in the vacuole? Plant cell Animal cell

What organelle is the arrow pointing to? Vacuole What is the function of the vacuole? Storage What is stored in the vacuole? Wastes and water Plant cell Animal cell

Review from yesterday Prokaryotic Cell Eukaryotic Cell

Prokaryote vs. Eukaryote No nucleus Simple Only one job at a time No internal membranes Bacteria cells! Nucleus Complex Multi- task Internal membranes Plant, animal cells

Prokaryotes and Eukaryotes both have… Plasma (cell) membrane Cytoplasm Ribosomes DNA

Plant Cells vs. Animal Cells

Plant vs. Animal Cells Plant Cell Animal Cell

Animal Cells No chloroplasts or chlorophyll Many small vacuoles No cell wall Centrioles – structures used in cellular division

Plant Cells Contain chloroplasts Chloroplasts contain chlorophyll (green) used for photosynthesis One or two large vacuoles Rigid cell wall No centrioles

Plant vs. Animal Plant Cells Animal Cells Have cell walls composed of cellulose Are rectangular in shape Have chloroplasts Have a larger vacuole than animal cells NO Cell walls! Are more round in shape NO chloroplasts Smaller vacuole.

Plant or Animal??

Plant or Animal??

Plant vs Animal Cells Animal cell Plant cell http://www.science.org.au/sats2004/images/kobe6.jpg 2/17/06

Does this boundary separate a plant or animal cell from the environment? What structure is indicated by arrow A? What structure is indicated by arrow B? A Inside of cell Outside of cell B

Does this boundary separate a plant or animal cell from the environment? What structure is indicated by arrow A? Cell wall What structure is indicated by arrow B? Cell or Plasma membrane A Inside of cell Outside of cell B

Cells must: Maintain homeostasis: temp and pH buffers

1.2 Analyze the cell as a living system 1.2.1 Explain how homeostasis is maintained in the cell and within an organism in various environments (including temperature and pH). Unpacked: • Explain how cells use buffers to regulate cell pH and how cells can respond to maintain temperature, glucose levels, and water balance in organisms. • Compare the mechanisms of active vs. passive transport (diffusion and osmosis). • Conclude how the plasma membrane structure functions. • Explain changes in osmotic pressure that occurs when cells are placed in solutions of differing concentrations.   4.2 Analyze the relationships between biochemical processes and energy use in the cell. 4.2.2 Explain ways that organisms use released energy for maintaining homeostasis (active transport). Unpacking: Conclude that energy production by organisms is vital for maintaining homeostasis and that maintenance of homeostasis is necessary for life. Examples: Active transport of needed molecules or to rid the cell of toxins; movement to avoid danger or to find food, water, and or mates; synthesizing needed molecules

Cell Adaptations in Unicellular Organisms

Unicellular Organisms Unicellular organisms are made of ONE cell. Since they are made of ONE cell, that cell HAS TO carry out ALL the functions of that organism!!!

Cilia Short hair-like projections from the membrane Cell movement View clip of Paramecium using cilia. You will need to close the powerpoint window for each video clip.

Flagella Long whip-like structure that extend from the cell membrane Click here to view a clip of a sperm cell using a flagellum (look closely, it is hard to see!!! Usually 1 or 2 on a cell Click here to watch video of cilia and flagellum.

Contractile Vacuole Contractile Vacuole – a structure that helps remove excess water out of the cell Euglenas live in freshwater so water enters their cells and they need a way to get rid of the extra water.

Eyespots Eyespot – organelle that detects light Euglenas can use their eyespot to detect light. Light is needed for the chloroplasts. Remember - chloroplasts need light in order to make food

Pseudopod Pseudopod – extensions of cytoplasm that are used to move as well as feeding This is an amoeba – it moves like a “blob.”

Cell Specialization

A Stem Cell Story http://www.youtube.com/watch?v=2-3J6JGN-_Y

What is it? Cell Specialization – cells throughout an organism can develop in different ways to perform different tasks (differentiate).

Types of Stem Cells Embryonic – have not differentiated into various cell types (these cells have the ability to become any type of cell) Adult – can only differentiate into certain types of cells. (IE…bone marrow stem cells can only become certain types of blood cells)

Cell Structure and Function Cells vary in size. Longest cell – nerve cells (up to 2 meters long) Smallest cell – bacteria Largest cell – egg cell

Cell Structure and Function Cells vary in shape. Shape is often related to function.

Red Blood Cells Round shaped disks that travel easily through blood vessels transporting oxygen

Xylem and Phloem Found in plants Xylem: transports water and minerals, moves materials up Phloem: transports food (sugar), moves material up and down

Nerve Cells Sends messages to other cells through electrical impulses

Skin Cells

Muscle Cells Long flat cells with lots of mitochondria

Sperm Cells Head that contains DNA and long whip like tail to help it swim

Egg Cells Large round cells with a nucleus

Levels of organization Cell  tissues  organs  organ system  organism

Cell Communication

http://www.youtube.com/watch?v=U6uHotlXvPo

Cell communication how cells communicate or relay information to each other.

1. Short Distance cells that are close to each other can send molecules (messages) directly through cell membrane.

2. Nerve cells electrical impulses (neurotransmitters) are sent from one nerve cell to the next.

3. Long distance signaling through hormones Hormones are released from one cell and travels through the blood stream to the target cell. The target cell receives the hormone message via a receptor protein found in the cell membrane.

Homeostasis

Homeostasis Process by which organisms maintain a relatively stable internal environment.

Examples: Regulation of Temperature Shivering when cold to produce heat Sweating when hot to cool down

Examples Regulation of pH Your blood contains buffers to keep pH between 7.2 and 7.6

Examples Blood Glucose Levels When glucose levels get too high, insulin is released to lower them

Examples Water regulation When your body needs water to maintain homeostasis, internal signals make you feel thirsty.