Cells

Active transport

Active transport, such as the sodium-potassium pump, uses ATP (energy) to transport molecules against their gradient, from an area of low concentration to an area of a high concentration. In the example of the sodium-potassium pump, sodium ions are moved to an area of high concentration outside the cell and potassium ions are moved inside the cell.

A bulk transport method

Bulk transport, which requires energy, making it a form of active transport, can be found in either endocytosis or exocytosis. These processes move large molecules into and out of the cell. One specific example is phagocytosis, which moves bacteria inside the cell and is a form of endocytosis that requires energy from the cell.

Facilitated diffusion

Facilitated diffusion, such as glucose transport, is a type of passive transport that requires a specific protein to carry out. In the glucose transport example, the GLUT, or glucose transporter proteins, allow glucose to be transported from a high concentration in the intestine to an area of low concentration in the circulatory system.

golgi apparatus

Packages proteins for transport out of the cell

Describe the structure and function of TWO eukaryotic membrane-bound organelles other than the nucleus.

Ribosomes are organelles made up of two different subunits that use amino acids to produce proteins for the cell. Lysosomes, which digest excess or worn out cell parts, are spheres made of a lipid bilayer.

cELL tHEORY

The cell is the most basic unit of life, all living things are made of cells, and all cells come from other cells through cell division.

hypotonic solution

water>salt, water flows into cell and lyses it

Prokaryotic and eukaryotic cells have some non-membrane bound components in common. Describe the function of TWO of the following and discuss how each differs in prokaryotes and eukaryotes. DNA

-contains genetic information -in loop vs. linear -found in cytoplasm vs. found in membrane bound nucleus

key events of cell theory

1665-Robert Hooke discovered cells by looking at cork under a microscope 1670-Leeweunhoek was the first to see living cells under a microscope 1833-Robert Brown discovered the nucleus 1838-Matthias Schleiden +Shwann proposed that all animal tissue is made of cells 1855-Rudolf Virchow discovered that cells arose from other cells

chloroplasts

turn solar energy into food, plant cell

Explain the endosymbiotic theory of the origin of eukaryotic cells and discuss an example of evidence supporting this theory. (2pts)

This theory says that eukaryotic cells come from prokaryotic cells absorbing each other and forming a symbiotic relationship. One piece of evidence that supports the endosymbiotic theory is that mitochondria have their own membranes, just as individual prokaryotic cells have membranes. The existence of many membrane-bound organelles found in eukaryotic cells supports the theory that they were once just prokaryotic cells that were absorbed by another prokaryotic cell.

nucleus

contains genetic info (DNA)

centrioles

control cell division

lysosomes

digest excess or worn out cell parts

isotonic

equal, water flows evenly

cell wall

gives structure (only in plant cell)

phospholipid bilayer

hydrophilic head, hydrophobic tail, held together by weak interactions

Ribosomes

make proteins from amino acids

cytoskeleton

moves things within the cell

smooth er

produces lipids and carbs

Prokaryotic and eukaryotic cells have some non-membrane bound components in common. Describe the function of TWO of the following and discuss how each differs in prokaryotes and eukaryotes. CELL WALL

protects + keeps shape -made of peptidoglycans vs. made of chitin + cellulose

cell membrane

regulates what enters and exits

hypertonic solution

salt>water, water flows out of cell

vacuole

stores food & keeps cell pressurized

rough er

stores proteins made by attached ribosomes