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Role of complement proteins

By: HWC, Views: 6420

• Non-specific and specific defense mechanisms work through the functions of complement proteins. • As soon as pathogens penetrate the physical barrier of the skin, other resistance mechanisms begin. • Cells, such as macrophages, phagocytize pathogens. • These cells increase exposu...

Protein catabolism - deamination

By: HWC, Views: 6850

• Digestion hydrolyzes proteins into amino acids, which are transported to the bloodstream. • Amino acids and proteins are not stored. • Instead, they are: • Oxidized to generate ATP. • Used to synthesize new proteins. • Converted to carbohydrates or lipids for storage (if e...

Membrane transport proteins - pores, gated channels and pumps

By: HWC, Views: 6764

• a Three different types of membrane ion transport proteins are required to produce and carry electrical signals: • Pores • Gated channels • Na+/ K+ pump • Pores are always open and allow the diffusion of Na+ and K+ ions across the membrane, down their concentration gradients...

Phases of an Action Potential - Resting Potential, Threshold, Rising, Falling, & Recovery Phases

By: HWC, Views: 6106

In this tutorial, we will review the phases of an action potential measured from a small area of a neuron's membrane. The action potential can be divided into five phases: the resting potential, threshold, the rising phase, the falling phase, and the recovery phase. When the neuron is at rest,...

Role of ATP in muscle movement

By: HWC, Views: 6837

• Muscle cells use ATP to power contraction and movement. • The hydrolysis of ATP to ADP releases • ATP can be regenerated by adding to ADP. • During muscular contraction, ATP molecules: • Energize the myosin head • Detach myosin from actin • ATP must be then regenerat...

Interspecific Competition Relationship - Competitive & Niche Differentiation

By: HWC, Views: 6325

In an environment with limited resources, any organisms that utilize the same resources will be in competition with each other. For example, let's look at two competing species of paramecium, a single-celled organism that feeds on bacteria. If we raise each of these species in isolation, both...

Simple Diffusion - Ion transport

By: HWC, Views: 6732

In the process of diffusion, a substance tends to move from an area of high concentration to an area of low concentration until its concentration becomes equal throughout a space. Ions must diffuse through membrane pores or gated channels. Pores are always open. More pores allow more ions...

Contraction cycle of a sarcomere

By: HWC, Views: 7184

• A single nervous signal releases Ca2+ ions into the sarcoplasm and initiates the contraction cycle. step 1. ATP hydrolysis • ATP provides the to move myosin molecules back into the energized configuration necessary to perform the power stroke. Step 2. Crossbridge attachment • Myosin...

Muscle cell structures - actin, myosin and titin filaments

By: HWC, Views: 6789

Once the muscle cell has been excited it will contract. • A muscle action potential will trigger the release Of Ca2+ ions into the sarcoplasm. • The Ca2+ ions bind to the regulatory proteins and trigger contraction. • Within skeletal muscle cells are structures that provide the ability...