Cellular respiration Photosynthesis vs.
Passive transport means there is no expenditure of energy ATP. Passive transport requires the substance to move from an area of high concentration to low concentration. Simple diffusion across membranes occurs when substances other than water move across the phospholipid bilayer between the phospholipids or through protein channels.
Substances that move across the membrane are usually small non-charged particles i. Oxygen, Carbon Dioxide, and Nitrogen or other lipids. Each protein channel structure allows only one specific molecule to pass through the channel.
For example, magnesium ions pass through a channel protein specific to magnesium ions. Active transport generally moves substances against their concentration gradient low to high concentration.
Many different protein pumps are used for active transport. Each pump only transports a particular substance; therefore cells can control what is absorbed and what is expelled. Pumps work in a specific direction; substances enter only on one side and exit through the other side.
Substances enter the pump from the side with a lower concentration. Energy from ATP is used to change the conformational shape of the pump. The specific particle is released on the side with a higher concentration and the pump returns to its original shape.
Good link for membrane transport https: Vesicles move materials within cells. The phospholipids in the bilayer are loosely packed together creating fluidity and allowing movement along the horizontal plane.
The hydrophilic properties of the phosphate heads and the hydrophobic properties of the hydrocarbon tails prevent flipping of the molecules across the vertical plane, maintaining the stable bilayer. Cholesterol embedded in the membrane will reduce the fluidity making the membrane more stable.
Endocytosis Plasma membrane is pinched as a result of the membrane changing shape.
Fluid droplets are engulfed and enclosed by the membrane. A vesicle is formed that contains the enclosed particles or fluid droplets, now moves into the cytoplasm.
The plasma membrane easily reattaches at the ends that were pinched because of the fluidity of the membrane.
Vesicles that move through the cytoplasm are broken down and dissolve into the cytoplasm. Exocytosis After a vesicle created by the rough ER enters the Golgi apparatus, it is again modified, and another vesicle is budded from the end of the Golgi apparatus, which moves towards the cell membrane.
This vesicle migrates to the plasma membrane and fuses with the membrane, releasing the protein outside the cell through a process called exocytosis.
The fluidity of the hydrophilic and hydrophobic properties of the phospholipids and the fluidity of the membrane allows the phospholipids from the vesicle to combine to the plasma membrane to form a new membrane that includes the phospholipids from the vesicle.
Video showing endocytosis and exocytosis Diagram of Endocytosis and Exocytosis to the right Applications and skills: Structure and function of sodium—potassium pumps for active transport and potassium channels for facilitated diffusion in axons.
Every cycle pumps three sodium ions out of the axon and two potassium ions into the axon. Tissues or organs to be used in medical procedures must be bathed in a solution with the same osmolarity as the cytoplasm to prevent osmosis.
Hypertonic solution — Is a solution with a higher osmolarity higher solute concentration then the other solution. Hypotonic solution — Is a solution with a lower osmolarity lower solute concentration then the other solution.Definitions of photosynthesis and respiration.
Photosynthesis is a process in photoautotrophs that converts carbon dioxide into organic compounds in the presence of sunlight.
Respiration is the set of metabolic reactions that take in cells of living organisms that convert nutrients like sugar into ATP (adenosine tri phosphate) and waste products. Balance with Photosynthesis.
Respiration is the antithesis to the process of photosynthesis, in which carbon dioxide and water are taken in by autotrophs, along with sunlight, to make glucose and.
The rate of photosynthesis is affected by a number of factors including light levels, temperature, availability of water, and availability of nutrients.
Pioneer trees, for example, are typically characterized by light-induced seed germination, high growth and mortality rates, short leaf life spans, high tissue nitrogen and phosphorus concentrations, low wood density, early reproductive maturation, and high fecundity, as well as high rates and plasticities of photosynthesis and respiration (Swaine and Whitmore , Raaimakers et al.
Photosynthesis is the process by which organisms that contain the pigment chlorophyll convert light energy into chemical energy which can be stored in the molecular bonds of . An interactive explanation of the aerobic respiration process, with equations and details of the movement of substances involved.