Science Unit 2

Prokaryotic

  • Cells that do not enclose their DNA in nuclei

  • Bacteria are Prokaryotic

  • Smaller and simpler than eukaryotic cells

  • Hey can grow, reproduce, and respond to the environment and some can even move by gliding along surfaces or swimming through liquids 

Eukaryotic

  • Cells that enclose their DNA in nuclei

  • Contain dozens of structures and internal membranes

  • Larger and more complex than prokaryotic cells

  • Many eukaryotes are highly specialized

  • Many types of eukaryotes, 

  1. Plants

  2. Animals

  3. Fungi

  4. Protists 

Organelles

  • Specialized structures

  • Means little organs

Cell Wall

  • The Cell Wall is the supporting layer around the Cell Membrane.

  • The Cell Wall’s main function is to provide support and protection for the cell

Cell Membrane

  • The Cell Membrane is a thin flexible barrier surrounding the cell

  • It controls what comes in and out of the cell and also protects it.

Nucleus

  • The nucleus is the control center of the cell

  • It also contains the DNA of the cell

Nuclear Envelope

  • The Nuclear Envelope surrounds the cells and is dotted with thousand of nuclear pores

  • It allows material to move in and out of the cell

Chromatin

  • Chromatin are found inside of the nucleus

  • They are thread like complexes of DNA that are bound to proteins

Nucleolus

  • The nucleolus is inside of the cell and is a small dense region

  • The nucleolus is where the assembly of ribosomes starts

Cytoplasm

  • Cytoplasm is the gel like fluid portion of the outside of the nucleus

  • It is where many organelles are found

Mitochondria

  • The Mitochondria are in nearly all eukaryotic cells and they contain their own small portions of genetic molecules in the form of DNA

  • They are the powerhouse of the cell and they convert the chemical energy found in food into substances that are more convenient for the cell to use

Endoplasmic Reticulum

  • Endoplasmic Reticulum are the passageways that carry materials around the cell

  • They become Rough Endoplasmic Reticulum when there are ribosomes on it.

Ribosomes

  • Small particles of RNA and protein that are found in the cytoplasm of all cells

  • They assemble proteins by following coded instructions from the DNA

Golgi Body

  • The Golgi Body modifies, sorts, and packages proteins and other materials from the RN for use inside the cell or to be released outside of it

  • it is a stack of flattened membranes in the cell and acts as the “UPS”

Chloroplast

  • Chloroplasts are the equivalent of solar panels in the cell, they take energy from sunlight and turn it into food and chemical energy during photosynthesis

  • They are green because they contain the chlorophyll

Vacuole

  • The Vacuole is a large sac-like membrane enclosed structure.

  • It stores fluids like water, salt, and carbohydrates.

Lysosome

  • Lysosomes are the cleanup crew of the cell

  • They breakdown lipids, carbohydrates, and proteins into small substances that can be used by the rest of the cell

Centriole

  • Located near the nucleus and help to organize cell division

  • In animal cells structures known as centrioles are also formed from proteins called tubulins

  • Not found in plant cells

Cytoskeleton

  • Helps the cell maintain its shape and its involved in movement made up of microtubules and microfilaments

Organic Compounds

  • Lipids, Carbohydrates, Nucleic Acids, proteins 

Macromolecules

  • BIG MOLECULES

Carbohydrates

  • Contains 

  1. Carbon

  2. Hydrogen

  3. Oxygen

  • The monomers found in carbohydrates are monosaccharides

  • They make up the cell membrane/wall and the cell uses them for energy

  • Some examples are bread and pasta

Lipids

  • Contains

  1. Carbon

  2. Hydrogen

  3. Oxygen

  • The monomers found in lipids are fatty acid and glycerol

  • Cells stores energy for later use 

  • Some examples are olive oil and butter

Proteins

  • Contains

  1. Carbon

  2. Hydrogen

  3. Oxygen

  4. Nitrogen

  • The monomers found in proteins are amino acids

  • They make up the cell structure and also carry out chemical reactions

  • Some examples of proteins are in meat and fish

Enzyme

  • Speeds up chemical reactions that take place in cells 

  • Without them many chemical reactions would not happen

Nucleic Acids

  • Contain

  1. Carbon

  2. Hydrogen

  3. Oxygen

  4. Nitrogen 

  5. Phosphorus

  • Monomers

  1. nucleotides

  • Function instruct cells in carrying out functions

  • Ex: DNA, RNA

Selectively Permeable

  • Some substances can pass through while others cannot

Diffusion

  • Moving from an area of high concentration to low concentration

  • It is the main method molecules use across the cell 

Osmosis

  • The diffusion of water through a selectively permeable cell membrane

Equilibrium

  • When the concentration of a system is the same throughout

  • Same concentration on both sides

Isotonic

  • Concentration of water inside the cell is the same as outside the cell

  • Cell looks normal 

Hypertonic

  • Low water concentration and high solute concentration outside the cell

  • water moves out of the cell 

  • Cell looks shriveled

Hypotonic

  • High water concentration and low solute concentration outside the cell 

  • water moves into the cell

  • Cell is larger and can pop

Passive Transport

  • The movement of dissolved materials through a cell membrane without the use of energy

Active Transport

  • Requires energy

  • Movement of materials against a concentration difference is know as active transport

  • The movement of materials through a cell membrane using cellular energy

  • Low to high concentration

Endocytosis

  • Endo = within                    process of taking material into the cell

  • Cyto = a cell

  • Sis = process

Exocytosis

  • Exo = outside                   process of releasing large amounts of material out of the cell

  • Cyto = a cell

  • Sis = process