Life Science Chapter 4 The cell in action

Diffusion The movement from areas of high concentration (crowded) to areas of low concentration (less crowded) Do not need energy

Osmosis Diffusion of water through cell membranes

Semipermeable Only certain substances can pass through

Channels Passageways in the cell membrane that allow small particles to pass through

2 types of particle transport 1.Passive 2.Active

Passive transport The movement of particles across a cell membrane without the use of energy

Active transport A process of transporting particles that requires the cell to use energy

Moving large particles into cell ENDOCYTOSIS The cell comes into Contact with A particle The cell membrane Begins to wrap around The particle Once the particle Is completely Surrounded, a vesicle Pinches off

Moving large particles out of the cell EXOCYTOSIS Large particles that Must leave the cell Are packaged in vesicles The vesicle travels To the cell Membrane and fuses With it The cell Releases the Particle to the Outside of the cell ???

Endocytosis The active transport process by which a cell surrounds a large particle and encloses the particle in a vesicle to bring the particle into the cell

Exocytosis An active transport process to remove large particles from the cell

Photosynthesis A process that the plants use to capture energy from the sun

6CO 2 + 6H 2 O + light energy  C 6 H 12 O 6 + 6O 2

In this process plants use the carbon dioxide and water with a little bit of sunlight to make glucose (a simple sugar) and oxygen…. Good thing that plants have their own way of pooing!!!

Pigments Main pigment in a plant cell is chlorophyll Chlorophyll is found in the chloroplasts These pigments absorb light energy

Two ways animals get energy from food 1.Cellular respiration 2.Fermentation

Respiration Means breathing

Breathing This is not cellular respiration Breathing only takes in oxygen and gets rid of carbon dioxide (our waste) Cellular respiration is a chemical process taking place in the cells

Cellular respiration C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + energy (ATP)

Glucose is broken down with the use of oxygen into carbon dioxide, water and energy (released as body temperature) ATP is the energy released That energy supplies most of the cells activities

ATP Adenosine triphosphate

Most of the cellular respiration in prokaryotic cells takes place in the cell membrane Eukaryotic cells have the process take place in the mitochondria

What is the connection between photosynthesis and cellular respiration?

6CO 2 + 6H 2 O + light energy  C 6 H 12 O 6 + 6O 2 C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + energy (ATP) Opposite with the exception of light energy being used by plants and ATP in food consumption

Fermentation Two kinds of fermentation: –One happens in muscles and produces lactic acid (buildup causes muscle fatigue and causes burning sensation) –Second kind happens in bacteria and yeast

Cell cycle The life cycle of the cell

Begins when the cell is formed and ends when the cell divides and forms new cells

DNA Hereditary material that controls all cell activities including making of new cells

Chromosomes DNA of a cell is organized into chromosomes

Cell cycle makes copies of DNA By copying chromosomes each new cell will be an exact copy of its parent cell

Prokaryotic cells Cells with no nucleus or membrane bound organelles Less complex than eukaryotic Cell division is called binary fission

Binary fission Results in two cells that each contain one copy of the circle of DNA Means splitting into two parts

Eukaryotic cells Cells with a nucleus and membrane bound organelles More complex than prokaryotic cells Chromosomes contain more DNA Different kinds of eukaryotic cells have different numbers of chromosomes The more complex organisms do not necessarily have more chromosomes

Fruit flies have 8 chromosomes Potatoes have 48 chromosomes Humans have 46 chromosomes These chromosomes pair up with each other so we have 23 pairs of chromosomes

Homologous chromosomes Pairs of similar chromosomes

Eukaryotic cell cycle Has three stages –Interphase –Mitosis –Cytokinesis

Interphase Cell grows and copies organelles and chromosomes After duplication the chromosomes are called chromatids Chromatids are held together with a centromere Joined chromatids twist and coil condensing into an “X” shape

Mitosis Four steps –Prophase –Metaphase –Anaphase –Telophase

Prophase Mitosis begins here Nuclear membrane dissolves Chromosomes condense into rodlike structures

Metaphase Chromosomes line up along the equator of the cell Homologous chromosomes pair up

Anaphase Chromatids separate and move to opposite sides of the cell

Telophase Nuclear membrane forms around each set of chromosomes Chromosomes unwind Mitosis is complete with this phase

Cytokinesis Without cell walls (animals and other eukaryotes) the division of the cytoplasm begins at the cell membrane where it begins to pinch inward to form a groove the eventually pinches all the way through the cell forming two daughter cells

Cytokinesis means the division of cytoplasm

Eukaryotes with a cell wall form a cell plate in the middle of the cell Cell plate contains the materials for the new cell membranes and new cell walls After the cell splits in two a new cell wall forms where the cell plate was