Transport in the Cell

Active and Passive Transport

How can molecules move through cells?

• Semi-permeable membrane: allows certain molecules to move in or out depending on their properties– Ex: if they are too big, they can’t go in

easily

• Membrane is made of (composition):– Bi-lipid layer

• 2 layers of lipids

– Proteins that transport materials across– Carbohydrates that act as identifiers

Fluid Mosaic Model-membrane is a fluid with a bunch of different components

Before we begin you must understand….

• Concentration-how much solute is in a solvent

• Why must molecules move?– To maintain homeostasis– Homeostasis-state of balance in

which the internal body remains in a normal range

– Molecules must move to maintain this

Biology 11/5

HW-Concept Map

1.Take out 7.3 wkst and 7.3 notes.2.Pick up your binder in the back. Put 7.3 reading guide in wkst section.

2 types of transport in the cell• Passive transport

– Molecules move down the concentration gradient• Area where there is

a lot of molecules to where there is very little

– Energy involved: NO• Active transport

– Molecules move up the concentration gradient• Area where there is

a few molecules to where there is a lot

– Energy involved: YES

Movie Time

http://www.brainpop.com/science/matterandchemistry/diffusion/

Username: cvbrainpopPassword: cheetah1

Type of Passive TransportDiffusion-movement of molecules

from an area of high concentration to an area of low concentration until equilibrium is reached – Equilibrium-equal distribution

• Molecules will move equally after this is reached.

– Simple molecules can move• Carbon dioxide, oxygen

Passive transport

Osmosis-Type of passive transport

• Water moves from an area of high concentration to an area of low concentration

– No energy involved– AKA: diffusion of water

Hypertonic and Hypotonic• Hypotonic-More water outside the cell than

inside– Distilled water– Water comes into the cell – Why? To balance out the concentration of

solutes• Hypertonic-More water inside the cell than

outside– Salt water– Water leaves the cell– Why? to balance out the concentration of

solutes

Isotonic

• Molecules are equal inside and outside the cell– Molecules move evenly across

the membrane

Biology 11/14

HW-finish concept mapAgenda: Stations; finish notesYou should be:1.Take out 7.3 notes2.Take out paper with station information.

Station Exploration• You will visit different stations.• At each station, there will be directions

telling you what conditions each item was place in or what to do with each item.

• On your paper, you need to write down a brief description of what you see and why.– Examples of answers for why: hypertonic,

hypotonic, diffusion, osmosis, decrease in turgor pressure, molecule movement

Why is water so important to a plant?

• Water fills the vacuole and the contents of the cell are pushed against the cell wall

• Produces turgor pressure• Gives the plant rigidity and the

ability to stand erect

Facilitated Diffusion-3rd type of passive transport

• Molecules move from an area of high concentration to an area of low concentration with the help of a carrier protein– Molecules attach to a specific protein– The protein allows it to move through the

membrane– Needed when molecules are too big or have

an electrical charge (ions!!)• Glucose (large molecules), Na+, Ca+, K+, Cl-

Active Transport-A reminder!

•Requires energy from the cell

•Move molecules from an area of low concentration to high

Endocytosis

•Process for bringing things into the cell

•Used for large particles (bigger than molecules, still microscopic)

•Requires energy

Phagocytosis• “Cell Eating”

• Very large particles taken in by cell (engulfed)

• “Cell Drinking”• Small bits of

liquid or other substances taken in

Pinocytosis

Exocytosis

•Process for moving large amount of material out a cell

Movie Time

http://www.brainpop.com/science/cellularlifeandgenetics/activetransport/

Username: cvbrainpopPassword: cheetah1

Bio 11/13

HW-finish wkst; Lab due Friday; test and flashcards Friday (25 from 7.3 and 10 from 7.4)

1. Turn in analysis questions. Put transport review in wkst section. This is a great study tool for the test. Put lab info in lab section.2. Take out 7.4 notes-we will finish this.

Movie time

• http://www.brainpop.com/science/cellularlifeandgenetics/passivetransport/

Username: cvbrainpopPassword: cheetah1

Section 7.4

• Unicellular-one celled– Bacteria, algae, yeast– One cell does all the work

• Multicellular-many celled– Plants, humans– Specialized cells do certain things

Specialization• Cell develop differently to perform

different tasks• All cells at one time in your body are

the same (stem cells)– Then they differentiate in fetal

development• Become different cells with different functions• Muscle cells-allow movement• Red blood cells-carry oxygen• Guard cells in plants open and close stomata

on a leaf.

Smallest level

Largest level

Group of similar cells

Group of tissues

Group of organsthat perform a specific function