I.Cells and Exchanging with the Environment

I.Cells and Exchanging with the Environment

I.Cells and exchanging with the environment

A.Diffusion: the movement of molecules from areas of high concentration to areas of low concentration

B.Osmosis: the diffusion of water

1.Cells are surrounded and made up liquids that contain water so osmosis is very important to cell functions

2.Pure water has highest concentration of H2O but when mixed with other substances for example salt the water concentration is reduced.

C.Moving small particles

1.Diffusion and osmosis are ways small materials move in/out of cell

2.Passive transport: moving substance across cell membrane without energy

a)High concentration to low concentration
b)Diffusion and Osmosis are example of passive transport

3.Active transport: moving particle across cell membrane with using energy

a)Low concentration to high concentration

D.Moving large particles using Vesicles

1.Endocytosis (within cell): the active transport process by which a cell surrounds a particle outside itself and encloses particle creating a vesicle to bring it inside cell

2.Exocytosis (outside the cell): the active transport process by which a cell releases a particle by enclosing it ina vesicle, inside the cell, moves it to the cell membrane where it fuses then is release by the cell

II.Cell Energy and how its made


1.Photosynthesis: the plant cell making energy from the sun, water and carbon dioxide by capturing it in the chloroplasts

a)Chlorophyll is the pigment that actually traps the sun’s light
b)Photosynthesis makes glucose, a carbohydrate, for the plant to store
c)6CO2 + water (6H2O) + sunlight = glucose (C6H12O6) and 6O2


1.Cellular Respiration: the process which the cells use oxygen to break down food

a)Food broken down and energy release
(1)Heat energy to maintain body temperature
(2)Energy to make ATP (energy molecules for cells)
(3)Glucose (C6H12O6) +oxygen 6(O2) Carbon Dioxide6(CO2) + water 6(H2O) + energy (ATP)

2.Relationship between Photosynthesis and Respiration: each need the products produced from one process to make energy

3.Fermentation: breaking down food into energy (ATP) without oxygen

a)Like in your muscle cells when you don’t get enough oxygen you build up lactic acid and get cramps

III.The Cell Cycle

A.The Life of a Cell is calledThe Cell Cycle

1.Cell cycle begin when cell formed and ends when cell divides

2.Cell needs to copy its DNA

a)DNA is located on the chromosomes

B.Prokaryotic Cells: Binary Fission: Splits into 2 part

C.Eukaryotic Cells more complex so need more complex process

1.Different eukaryotic cells have different number of chromosomes

a)Humans have 23 pairs or 46 homologous chromosomes

D.Making Eukaryotic Cells

1.Interphase – copy DNA

2.Mitosis a process of cell division in eukaryotic cells (Asexual Process)

a)Prophase: chromosomes condense from long strands to rod structures
b)Metaphase: nuclear membrane breaks paired Chromatids line up on cell equator
c)Anaphase: Chromatids separate and move to opposite sides
d)Telophase: Nuclear membrane reforms around each set of chromosomes: Mitosis is complete

3.Cytokinesis: cell pinches in two for animal cells and in plant cells a cell plate is formed between cells