C E L L S

Cell Theory

1. All living things are made up of one or more cells. 2 The cell is the basic unit of life. 3 all cells are made from, pre-existing cells. * All organisms including: animals, plants, fungi, micro-organisms are made of cells.

Plant and Animals Differences

1. plant cells have a cell wall, where as animal cells only have a cell membrane. 2 plant cells have chloroplasts, animals cells do not. 3 Plant cells have a large vacuole, where as animals only have a small vacuole.

Cellular Respiration Reaction

6 H12 O6 + 6O2=6CO2 + 6H2O (+ energy)

Photosynthesis Reaction

6CO2 + 6H2O = (light energy) C6 H12 O6 + 6O2

Semi-permeable membrane

A Semi- permeable membrane means that some particles will be able to pass through the membrane, however some larger particles cannot, meaning, they will need to travel through the protein channels.

Tissue

A group of cells which preform the same function

System

A group of organs which function together to help the organism survive.

Organ

A group of tissues which work together to perform the same function.

Cytosol

A jelly-like liquid which consists of water containing dissolved solutes. The organelles are suspended in it.

Glycogen

A large chain of glucose molecules that also has branches. Animals store their energy in this form.

Starch

A long chain of glucose molecules linked. Plants use starch to store energy in the stems or roots. Animals can digest starch to get starch.

Vacuole

A membrane bound sac that contains water and solutes. They can store nutrients and wastes. In plant cells they may hold water to keep the plant rigid. They hold onto things that the cell may need and slowly break down the things that the cell doesn't. *large in plants- take up space- well watered plants become turgid. *small in animals

ATP

A molecule created in cellular respiration, it is the chemical which the cell uses for energy.

Enzyme

A natural catalyst (speeds up a reaction)

Endoplasmic reticulum

A series of channels that transport substances within the cell. The rough ER is covered in ribosomes and the smooth is not. Structure: it is attached to the outer membrane of the nucleus and it's walls are made of membranes.* endoplasmic reticulum with lots ribosomes attached is known as the rough endoplasmic reticulum and endoplasmic reticulum without ribosome attahced is known as smooth endoplasmic reticulum. *transports proteins synthesized by ribosomes.

Glucose

A simple sugar that stores energy in its chemical bonds. When the bonds are broken down, energy is released. Glucose is a monosaccharide.* can be joined together in various complex carbohydrates for energy storage * used to drive other reactions and processes in the cell.

Animal Cell

Animal cells are eukaryotic and have the 4 common things in cells. They also have a nucleus, mitochondria, E.R and Golgi apparatus.

Chloroplasts

Are found in plant and some algae. They are the sight of photosynthesis. It contains chlorophyll which is the green pigment which gives them their coloring. * membrane bound organelles

Eukaryotes

Can be both unicellular and multi cellular, have a nucleus which holds the DNA and other membrane bound organelles. They are larger and more complex. E.g. Animals or plants, fungi and protists

Organelles

Cells are made up of organelles that each have different roles. Organelles differed depending on the cell type. *they are the cells organs

Golgi apparatus

Channel that transports substances out of the cell.this is made of several layers of membranes. * AKA the Golgi apparatus and Golgi complex

Prokaryotes and eukaryotes

Differences Prokaryotes - very simple - lack a nucleus - single-celled - eg. bacteria, algae Eukaryotes - more complex - contain a nucleus - multicellular - eg. plant cell, animals cell, fungi Similarities - both composed of cells - each cell is surrounded by a cell membrane

Passive transport

Diffusion of molecules across the cell membrane. It does not require energy.

Facilitated diffusion

Diffusion that allows larger particles that cannot enter the cell through the cell membrane to enter the cell through protein channels.this does not require energy as molecules still move down the concentration gradient. Example: water enters the cell through facilitated diffusion

Cilia

Hair like structure which aid in movement, by beating in coordinated waves. An example of this is that they aid in the movement of mucus and dirt out of the lungs.

Prokaryotic cells

Have 4 common things to all cells and also often have a cell wall (different to plant cell wall).

Cell membrane

It is a semi-permeable membrane (lets some particles through) it acts as a skin around the cell. It controls the movement of food, oxygen and water into the cell and waste products out of the cell. In animals cells, it is what holds the cells together. *protective layer, inside cell wall, controls movement of food, oxygen and water into and out of the cell.

Cell wall

It is found in cells such as plants and fungi but not animal cells. It helps the plant keep upright and rigid. It contains little holes to let out wastes and nutrients. It is made of cellulose.

Cellulose

Large molecule formed when chains of glucose join together. This is used as a structural feature in plants (cell walls). Animals cannot digest it because it is too big and bonded too strongly.

Light microscopes

Light microscopes are used to magnify objects of research such as cells. The total magnification is the objective lens x the ocular lens.

Nucleolus

Located in the nucleus, contains most of the DNA and produces ribosomes.

Protein

Made from chains of amino acids. e.g. hair and nails

Fat

Made up of one glycerol molecule and three fatty acid molecules. They are made of carbon, hydrogen and oxygen.

Lysosomes

Membrane bound organelles that are filled with a fluid containing digestive enzymes. They digest large molecules and unwanted things in the cell.

MRS GREN

Movement: does the object move? Respiration: does it breathe? Sensitivity: it is sensitive to it's surroundings? Growth: does it grow? Reproduction: does it reproduce? Excretion: does it get rid of wastes? Nutrition: does it eat or consume?

animal cell- hypotonic, isotonic, hypertonic

Picture 1: the Hypotonic medium is drawing the water out of the cells causing the cell to shrink. Picture 2: The isotonic medium is drawing the solution in and out of the cell, causing it to the same size. Picture 3: the Hypotonic solution is drawing water into the cell causing it to become plump.

Plant cell- hypertonic, isotonic and hypotonic

Picture 1: when water moves out the plant cell (hypertonic), the cell shrinks and the membrane pulls away from the cell wall. This is called Plasmolysis. Picture 2: when water moves into and out of the plant cell at the same. (isotonic), the cell is in equilibrium. Because it is not plump and full it is called flaccid. Picture 3: because plant cells have rigid cell walls, the cell doesn't rupture when water moves into it (Hypotonic), It becomes plump and full. This is called a turgid plant cell.

Plant cell

Plant cells have the same organelles as animal cells as well as chloroplasts, cell wall and a larger vacuole.

Anaerobic respiration

Respiration that occurs without the use of oxygen. It produces less energy. Fact: only 2 ATP molecules are produced for every glucose molecule. Example: muddy water of a river bottom- no oxygen

Aerobic respiration

Respiration using oxygen. It produces a lot of energy. Fact: One molecule of glucose can produce 38 ATP molecules

Prokaryotes

Single celled organisms that do not have a nucleus and are small and simple. They also have few internal structures. E.g. bacteria *they are abundant in air, soil, water and on most objects

Fatty acids

Tail like molecules that make up fats

DNA

The DNA holds the genes (instructions) that are responsible for providing the cell with its unique characteristics. DNA in every cell is the same, but depending on the cell type, some genes may be switched on or off.

Glycerol

The backbone of fat molecules.

Amino Acid

The building blocks of protein. The order of genes determines the amino acids used. This determines the different protein that is produced by the ribosome.

Cytoplasm

The cytoplasm is the cytosol and all the organelles inside the cell except the nucleus.

Active transport

The movement of particles across a semi-permeable membrane from an area of low concentration to an area of high concentration. Requires energy because it is going against the concentration gradient. The molecule that provides the energy is ATP.

Diffusion

The movement of particles from an area of high concentration to an area of low concentration. It does not require energy. Example: blood flow between lungs and blood stream O2 and CO2

Osmosis

The movement of water molecules across a semi-permeable membrane into an area of higher solute concentration.

Net movement

The movement of water molecules in and out of the cell. Example: there is a net movement of water into the cell.

Nucleus

The nucleus is the control centre of the cell. It controls movement, reproduction and chemical reactions in the cell. It also contains the DNA of the cell. Structure: enclosed with a double membrane called the nuclear envelope or nuclear membrane. This has many pores through which material may enter or leave the nucleus. The Nucleolus is the main structure in the nucleus, it contains most of the DNA and produces ribosomes which move out of the nucleus into the rough ER

Cellular respiration

The process of breaking up sugars into a form that the cell can use as energy. All cells do this.

Photosynthesis

The process of converting light energy to chemical energy and storing it in the bonds of sugar molecules. It occurs in plants, some bacteria and some algae. Reactants: carbon dioxide and water Products: Glucose and oxygen

Mitochondria

The site of cellular respiration in eukaryotes, they provide the cell with energy.* powerhouse of the cell

Ribosomes

They are responsible for producing proteins (protein synthesis) out of amino acids and are found on the rough endoplasmic reticulum but also found floating freely in the cytosol.Structure: they are very small and not enclosed by a membrane. In Prokaryotic cells they are smaller however in eukaryotes many of the ribosomes are attached to the ER otherwise they float freely.

Flagella

They tail like structures which are attached to the cell membrane and protrude through the cell wall. When rotated, they create movement of the cell.

Phospholipid bilayer

Two layers that make up the cell membrane. It is made of phosphate and lipid molecules.

Plasmolysis

When a plant cell is placed in a hypertonic solution and the water is drawn out of the cell. The vacuole shrinks, which causes the cell to shrink and the cell membrane to pull away from the cell wall.

Flaccid

When a plant cell is placed in an isotonic solution and the water enters and leaves the cell at the same rate, the cell is not plump and full.

Turgid

When a plant cell is placed in hypotonic solution and becomes plump and full of water. In plant cells the cells does not erupt when. Water continuously moves in because of the cell wall.

Hypertonic

When the concentration of solutes is higher outside the cell than inside meaning water molecules move out of the cell faster than they move in.

Hypotonic

When the concentration of solutes is lower outside the cell than inside meaning water molecules move into the cell faster than they move out.

Isotonic

When the concentration of solutes is the same inside the cell and out therefore the water molecules move in and out at the same rate.

Equilibrium

When the rate at which molecules enter and leave the cell is equal. (Concentration is equal on both sides of the membrane).

Concentration gradient

When there is a difference in concentration in two different areas across a semi-permeable membrane.

What do all cells have?

all cells have DNA, ribosomes, cell membrane and cytosol