what does it mean to say something is alive?

What does it mean to say something is ALIVE?

8 Characteristics of Living Things

• Made of cells• Reproduce• Based on a universal genetic code• Grow and develop• Obtain and use materials and energy• Respond to their environment• Maintain a stable internal environment• Taken as a group, living things change over time

Made of CellsLiving things are…

Living things have…

The ability to reproduce

Based on a Universal Genetic

Code: DNA

Living things are…

Grow and Develop

Living things …

Obtain and Use Energy - METABOLISMLiving things …

Respond to the

Environment –Stimulus

Living things…

Maintain a stable internal

environmentHOMEOSTASIS

Living things …

Evolutionary Adaptation: Species change over time

Living things undergo…

Cell Structure and Function

Look at the words below. Can you order them from simple to most complex?

BiomoleculesOrganelle Cell Tissue Organ Organ System

Organism

What we will be looking at the next few weeks

The Cell TheoryAll living things are composed of

cells. If its not made up of at least one cell, it is NOT living!

Cells carry on similar functions like obtaining energy and removing waste

Types of CellsTwo kinds of cells depending on

whether they have a nucleusProkaryote

Eukaryote

Genetic material

ProkaryotesUsually small and

simple

Genetic material (DNA) is not contained in a nucleus

The ONLY prokaryotes in the world are BACTERIA.

Prokaryotic Cells

EukaryotesUsually larger and

more complex than prokaryotes.

May be unicellular like an amoeba or multicellular like a plant

Contain dozens of specialized structures called organelles.

Includes protists, fungi, plants and animals.

Eukaryotic cell structureTwo major parts:

NucleusCytoplasm-portion of the cell outside the

nucleus

Eukaryotic cells

Nucleus-The control centerFunction:

Contains almost all of the cell’s DNA for coding proteins and other molecules.

DNA is found on chromosomes which contain genetic information.

Nucleus-The control centerStructure:

Surrounded by a double membrane called a nuclear envelope. It is dotted with many pores (holes) to allow materials (RNA, proteins, etc) in and out of the nucleus.

Small internal region called a nucleolus where ribosomes are made.

RibosomesFunction:

Site of protein assembly.

Structure:Small pieces of RNA

and protein found throughout the cell.

Endoplasmic ReticulumFunction:

Site where lipid parts of cell membrane are made, along with proteins and other materials to export from the cell.

Structure: Rough ER- has ribosomes

on surface to assemble proteins

Smooth ER-NO ribosomes on surface

Golgi ApparatusFunction:

Modify, sort, and package proteins and other materials from the ER for storage in the cell or release from the cell. It puts the finishing touches on proteins.

Structure: Stack of closely

packed membranes

You have 3 minutes to compare your notes with a neighbor. Be sure to ask questions and fill in any blanks you may have in your notes at this time.

Lysosomes-The Clean Up CrewFunction:

Breakdown of lipids, carbohydrates and proteins into small molecules to be used by the rest of the cell

Breakdown used up organelles

Get rid of all “stuff” in the cell

Structure: Small, filled with

enzymes

Vacuoles - StorageFunction:

Stores water, salts, proteins and carbohydrates

Structure:Sac-likePlant cells have one

large central vacuoleAnimal cells have

many small vacuoles

Mitochondria - EnergyFunction:

Convert chemical energy in food into materials easier for the cell to use.

Structure: Enclosed by two

membranes with the inner membrane folded up.

Contains it’s own DNA (unlike other organelles) that is identical to your mother’s!

Chloroplasts – Energy in Plants Function:

Captures energy from the sun (solar energy) and changes it into food (chemical energy) for plants (photosynthesis)

Structure: Surrounded by two

membranes Contains own genetic

information like mitochondria

Contains green pigment called chlorophyll

Not found in animal cells!

With your neighbor, list similarities and differences between mitochondria and chloroplasts. Be prepared to share with the class.

Cytoskeleton- structure and support

Function:Helps maintain cell

shape Helps with

movement of the cell (i.e. flagella and cilia)

Structure:Two types:

microfilaments and microtubules

Cell MembraneFunction:

Regulates what enters and leaves the cell

Provides protection and support

Structure: Double membrane

called a lipid bilayer Flexible structure that

forms a strong barrier between the cell and its surroundings

Cell WallFunction:

Provides support and protection for the cell

Structure:Lies outside the cell

membraneFound in plants,

algae, fungi and many bacteria

NOT FOUND IN ANIMAL CELLS!

Individually, write down 3 differences between plant and animal cells.