Cell Organelles

​Cell Membrane

• ​lipid barrier

• ​encloses the cytoplasm

• ​controls what enters and exits the cell

• ​protects and gives cell some structure

• ​in both plant and animal cells

​Cell Wall

• ​tough, protective barrier

• ​made of cellulose

• surrounds the outer membrane of plant cells

• ​forms stiff and rigid structure to help plants grow tall

  NOT in animal cells

Mitosis

Phases of Mitosis

Prophase, Metaphase, Anaphase, Telophase

Prophase

Chromatin condenses to form visible chromosomes. The nuclear envelope disappears. More structures also appear.

Metaphase

Chromosomes line up in the middle

Anaphase

Centromeres break and sister chromatids pull apart when the spindle fibers shorten

Telophase

Chromosomes unpack to less visible chromatin and nuclear envelope. The cell begins to pull apart by pinching in the middle before it divids.

Punnett Squares

by Neotha Moses-Williams

Potential and Kinetic Energy

Unit 4 7.P.2.1

Energy

How is energy defined in science?

* The ABILITY to move matter or CHANGE matter in some other way.

 * The ability to do WORK.

Name two types that energy.

* POTENTIAL ENERGY

* KINETIC ENERGY

Potential Energy

- STORED energy or ENERGY ready to be released.

Kinetic Energy

- energy RELEASED or energy in MOTION.

Energy Transformation

Chemical Energy

Energy that is released from chemical reactions

Thermal Energy

Also known as heat energy , the sun is an example of thermal energy that is transferred

Electrical Energy

A Light bulb is an example of the use of electrical energy

Electromagnetic Energy

One form of Energy can Transform into another form of energy

Check the examples on the right

Remember !!!

Newton ?

One more time

Let us look at more examples of energy transformation

Last Example

Let us look at this one last time before you go onto a short quiz

Magnets interact through their magnetic fields

They have two poles, north, and south.

Their fields always move north to south.

Opposite poles attract

Like poles repel

What is electricity?

Here is a short video about electricity and some things that we need to know to move forward. 

Charges of Subatomic Particles

• Protons are in the nucleus of the atom and have a positive charge. (+)

• Neutrons are in the nucleus of an atom and have a neutral or no charge.

• Electrons orbit the atomic nucleus and have a negative charge. (-)

Current & Circuits

• Ampere: continuous flow or charge that we call an electric current. This is measured in amperes or amps.

• Voltage: pressure in the wire that creates a difference in potential energy. We measure this in Volts.

• Resistance: the tendency for certain materials to slow or impede the flow of electrons. This is resistance and we measure it in Ohm's.

• Electrical current will flow through a connected conductor that does not have any gaps or empty spaces. We call those loops circuits.

What is a circuit?

• Series circuits are circuits with only one path for electrons to flow.

• Parallel circuits have more than one path for electrons.

• These circuits are used for different purposes.

• You have circuits in any place that has electricity.

Conductors and Insulators

Conductors allow for an easier flow of electrons.

Insulators resist the flow of electrons.