Transport

Transport (def) The absorption of materials into the cells and distribution of materials within the cells and throughout the organism (circulation) A. Absorption – the passage of materials through a cell membrane into the cytoplasm of the cell

The Cell Membrane Structure of the cell membrane a. consists of lipids and proteins b. 2 layers of lipids with proteins within it a. Fluid Mossaic Model is used to represent the C.M.

The Cell Membrane

Properties of the Cell Membrane Allows the passage of many small particles (water, gases, dissolved ions, nutrients) These all pass by diffusion Large molecules like starch, Fats, proteins are too large to pass through They must first be Chemically Digested and this is aka….

3. The Funtions of the Cell Membrane a. Selectively regulates the passage of materials in and out of the cell – the bouncer! b. Does it prevent all harmful substances from entering the cell? c. Helps to regulate homeostasis of the cell

Methods of transport across the cell membrane: Particles = (O2, CO2, Food, Wastes) Water = water Diffusion (passive Transport) – the movement of particles from an area of high concentration to an area of lower concentration a. Requires no energy

2. Osmosis – a. the diffusion of water from an area of high concentration to an area of lower concentration b. Requires no energy

Notice that it is the movement of water

3. Active Transport a. the movement of particles across the cell membrane b. from an area of low concentration to an area of high concentration c. energy required

Phagocytosis – the process by which the cell engulfs large particles using pseudopods (False Feet) a. energy required

Pinocytosis (cell drinking) a. The process by which dissolved particles are swallowed up by the cell b. “pinching in” of the cell membrane a. Energy required

Method of transport Movement of what Direction of flow Energy Required

C. Types of Circulation 1. Intracellular circulation a. The movement of materials throughout the cell b. Done by diffusion, Cyclosis (cytoplasmic streaming) 2. Circulation within the organism a. the passage of materials throughout an organism

D. Adaptations for Circulation in Plants Bryophytes (Lack Vascular tissue) Tracheophytes (More Complex and have a true vascular network Xylem Phloem 1. Made of dead cells 2. Transports water up the plant to the leaves Made up of living cells Transports water and food ( ) down

Transport in roots Adapted to anchor the plant and to absorb water Growth of the root is by cell division ( ) at the root tip Root Hairs- inc. surface are for maximum water absorption and to anchor the plant in the ground

onion root tip

Mitosis in the onion root tip

2. Transport in Stems Also contains Xylem and Phloem Supports the leaves for inc. light exposure for photosynthesis

3. Transport in Leaves Transport throughout the leaves is done by the vascular tissue contained in the vascular bundles

Mechanisms of transport in the xylem (3 types listed weakest to strongest) Root pressure- forces of osmosis and active transport creates a pressure inside the root cells Capillary action (Stems) 1. the ability of water to rise in narrow tubes

Transpiration pull 1. As water evaporates from the airspaces of the leaves (stomates), this creates an upward force that draws the water up from the roots and through the stems 2. Strongest acting force to draw water up the plant

Mechanisms of transport in the xylem Root Hairs- inc. surface are for maximum water absorption and to anchor the plant in the ground

Adaptations for Transport in Animals and Protozoans Protozoans (Amoeba and Paramecium) Water in the environment acts as the transport medium 2. Absorption occurs directly across the cell membrane by diffusion and osmosis 3. Circulation within is by Cytoplasmic Streaming (Cyclosis)

2. Hydra a. All cells are in direct contact with the watery environment b. Absorption occurs into each cell by diffusion and osmosis

a. Many cells are not in direct contact with 3. Earthworm a. Many cells are not in direct contact with the environment b. Nutrients, O2 and Wastes are transported by fluid called blood 1. contains hemoglobin (Like Human) a. carries O2 and CO2 c. has a closed circulatory system (like human) d. Aortic Arches (5 Hearts)} to pump the blood e. O2 is absorbed through the moist skin covered with mucous

a. Has an open circulatory system that carries 4. Grasshopper a. Has an open circulatory system that carries blood into an open space-sinus b. Blood is not adapted to transport gases 1. no hemoglobin c. blood is pumped by a Dorsal Pulsating Blood Vessel