Cell Structure and Function

Cell Structure and Function Chapter 3 Size Comparison

Domain II: Cellular Basis of Life *Explain the cellular basis of life *Homeostasis *Transport cellular material through cell membrane *Stem Cells

What is a Stem Cell? • What have you heard about stem cells? • Where do you think stem cells come from? • What are stem cells for? • What is a cell? • What do you think is the benefit of stem cells? Cute Stem Cell Animation

Name the 3 parts of the Cell Theory? • 1) Cell is the basic unit of life • 2) All organisms are composed of cells • 3) All cells come from pre-existing cells

Who were the initial cell Scientists? Pg.71 • Robert Hooke 1665. First to see a cell. Named it after Monk Cells. (Cork) • Anton van Leeuwenhoek 1673. 1st to see microscopic organisms.

What characteristics are needed to consider something alive? • 1) Require food for energy • 2) Use energy to maintain homeostasis • 3) Respond to stimuli • 4) Grow and develop • 5) Reproduce similar offspring • 6) Ability to pass genetic information • 7) Made of cells

What is the difference between a multicellular and unicellular organism? • Unicellular – exist as a single independent cell. Example: amoeba • Multicellular- organisms that exist as specialized groups of cells. • Order of cellular specialization: cells, tissues, organs, organ systems, organism

Which of the following is a correct statement regarding tissues? • A) Tissues hold organs together • B) Tissues form plasma membranes • C) Tissues are composed of organs with several functions • D) Tissues are composed of cells with similar functions • Answer: D

What is the difference between a prokaryote and a eukaryote? • Prokaryote-No membrane bound organelles. Only bacteria are considered prokaryotes. pg.72 • Eukaryote- Contains membrane bound organelles, including a true nucleus. Cell Comparisons

Which of the following is an example of a prokaryotic cell? • A)An animal cell • B) A bacterial cell • C) A fungal cell • D) A plant cell • Answer : b, both archae and Eubacteria are prokaryotes

Fluid-Mosaic Model What do all cells have in common? • Have a plasma membrane- semi-permeable structure surrounding the cell • Cytoplasm- jelly-like substance where cells chemical reactions occur as well as where organelles are found.

Stem Cell Differentiation How are cells different? • Size: Cells must be small for diffusion. The closer the surface Area/Volume ration the more diffusion. Shape: Fig 4-2. Long, Flat, Branching, etc. • Type of organelles and the number of each kind. (Red blood cells have no nucleus, Animal cells have no cell wall.) • Different types of cells have different needs therefore different structures. What is a stem cell?

What is an Organelle? • Part of a cell that performs a job. Like an organ does a job for the body organelles do the same for a cell. United streaming video clip Cell Movie: Amoebas & Animal Cells

Which organelles are found in plant cells but not in animal cells? • Plastids such as Chloroplast- capture solar energy for photosynthesis • Cell Wall- Adds structure and support to the cell • Plants also have much larger vacuoles for storing water then animal cells. Classzone Animal Vs. Plant

Define the following organelles: Golgi bodies, Mitochondria, Nucleus, Ribosome, and Vacuoles. • Golgi bodies- package and distribute lipids and proteins • Mitochondria- powerhouse of the cell, transforms energy

Definitions continued… • Nucleus- contains DNA which controls cellular activities • Ribosomes- produce proteins, found on the rough ER • Vacuoles- store substances such as water.

Define the following organelles:Smooth Endoplasmic Reticulum (ER), Rough ER, • Smooth Endoplasmic Reticulum (ER): Make Fats such as steroids. • Rough ER: Contain Ribosomes. Package and ship proteins made on Ribosomes.

Organelles Continued • Lysosome: Contain Digestive enzymes. Think SOS… • Nucleolus: Ribosomes and other RNA are synthesized. Great Lysosome Short Movie

Define the following organelles • Flagella: Whip like structure made of microtubules. Few in number and long. • Cilia: numerous short hair-like structures. Also made of Microtublules. Flagella and Cillia Video Clip Very Good!

In the animal cell, in which cell part does cellular respiration occur? • A) • B) • C) • D) • Answer: A Mitochondria Organelle Review Link Organelle Self-Quiz

Review: Which of the following is a characteristic of all living things? • A) Cellular Structure • B) Nervous System • C) Chlorophyll • D) Hemoglobin • Answer: A

Review: What is homeostasis? • Maintenance of internal equilibrium • Example: Body to returning to normal temperature (98.7) after a fever.

Which of the following statements best demonstrates homeostasis? • A) The intestine has a large surface area. • B) Humans tend to have 5 fingers on each hand. • C) Humans sweat when they get hot • D) Cells have maximum attainable size. • Answer:C

Back to Stem Cells! • How are stem cell made? • Why do you think stem cells exist? • Do differentiated cells have different organells? Making Stem Cells

Ch 3.4 & 3.5: Homeostasis and Transport • How do substance enter and exit a cell? • What is the difference between active and passive transport? • How does the chemical make-up of the plasma membrane affect what can enter and exit the cell? Membrane Transport

The plasma membrane only allows certain things to enter and exit the cell. What is this called? • Selectively permeable membrane or selectively permeable

What is passive transport? Name and describe the 3 types. • Passive Transport- movement of substance of substances across the plasma membrane without the use of energy. Passive Transport

The Three Types Diffusion: movement of substances across the plasma membrane from high to low concentration Osmosis: diffusion of water across the plasma membrane from high to low concentration Facilitated Diffusion: carrier molecules transport larger substances across the membrane from high to low.

What is active transport? Describe the two major types. • Active Transport: uses energy and carrier molecules to move substances across the plasma membrane from low to high concentrations (against the concentration gradient) Active Transport

The two types of Active Transport • Endocytosis: process by which large particles are brought into the cell • Exocytosis: process by which large particles leave the cell Endo/ Exocytosis

Substances that are too large to be moved across the plasma membrane can be engulfed through the process of … • A) Diffusion • B) Endocytosis • C) Exocytosis • D) Osmosis • Answer: B • Endo= inside, Exo= Outside, cyto=cell, osis= process or action

There are 3 types of solutions a cell can be in. • 1) Hypotonic • 2) Hypertonic • 3) Isotonic Hypo/Hyper/ Iso Solutions Hypo/Hyper/ Iso Scroll Down Red blood cell

Describe a cell in an isotonic solution. • Iso= the same. The concentration of the solution is the same inside and outside the cell. • The cell stays the same size. • There is no net movement across the plasma membrane (things enter and leave the cell at the same rate)

Describe a cell in an hypertonic solution. • Hyper= above. The concentration of the solution is higher outside the cell than inside. • The cell shrivels in size. • Water leaves the cell at a faster rate then it enters.

Describe a cell in an hypotonic solution. • Hypo= below. The concentration of solutions is lower outside the cell then inside. • The cell swells or pops in size. hyPO=POP • Water enters the cell at a faster rate than it leaves

A student is making a model to demonstrate how cells respond to solutions with varying concentrations of salt and water. She soaked a kidney bean in distilled water until it started to swell. In what kind of solution should she put the swollen bean to cause it to shrivel? • A) Acidic • B) Basic • C) Hypertonic • D) Hypotonic • Answer: C

Cell Structure and Function