In a frog’s circulatory system, it consists of a 3 chambered heart where the oxygenated and deoxygenated blood is mixed together in the ventricle. The purpose of this lab report is to observe the dissection of not only a frog, but a bird (pigeon), rats, crayfishes and starfishes. This report will discuss the observations of mainly a frog (bullfrog) and comparing these observations to a pigeon. The comparison chart consists of organs, structure, and function, and relationship between the structure and function. Materials * Dissection kit * Ruler * Scalpel * Scissors * Tweezers * Pointers * Pins * Camera * Pen * Notebook * Animal * dissection instruction manual * tray Digestive System Observations Animal’s Major Organs | Structure of Bullfrog | Structure of Pigeon | Function of Organ | Structure and Function Relationship | Liver | -dark in colour- large-wrapped around most organs- soft in texture-squishy | -large-brown/red colour-takes up large amount of space-above pancreas and intestine | -Breaks down toxins and fats-absorbs nutrients | -located where digestive system is to process fats and toxins-coloured is due to blood | Gall Bladder | -pea size- dark colour
Abstract Sliding filament theory of muscle contraction suggests existence of an optimal muscle length associated with maximum stimuli-generated tension. This hypothesis is tested in vitro by measuring muscle tensile response to fixed voltage stimulations under length alterations of the gastrocnemius of Xenopus laevis. Muscle length is mechanically varied by shrinking or extending and an attached force transducer records the tension generated by the fixed stimuli. Our results indicate greatest tensile response of about 3.2 N when muscle length is 30 mm. The response diminishes as deviations from this optimal length increases.
Therefore, platelets undergo degranulation the exocytosis of their cytoplasmic granules and release of factors that promote hemostasis. Aggregation is occurs when serotonin (vasoconstrictor), ADP (attracts more platelets and stimulates their degranulation), and thromboxane A2 (stimulates degranulation and vasoconstriction) are released. Thus it can quickly seal a small break in blood vessel. Coagulation is the last process of the hemostasis. It has three ways; intrinsic, extrinsic and common pathways.
[TYPE THE COMPANY NAME] DIFFERENCE BETWEEN THREE MUSCLE TYPES SKELETOL, SMOOTH AND CARDIAC MUSCLE ... GAOLATLHE THABISO KWENAMORE 24 SEPTEMBER 201101827 BIO 231 INTRODUCTION Muscles are multicellular contractile units. They are divided into three types which are skeletal muscle, smooth muscle and cardiac muscle and classification is done according to their structure, location and their function (Tortora and Derrickson,2011). Skeletal muscle is mainly responsible for the movement of the skeleton, but is also found in organs such as the globe of the eye and the tongue. It is a voluntary muscle, and therefore under conscious control, skeletal muscle is specialized for rapid and forceful contraction of short duration (Bevan et al,1996). In describing the cellular components of skeletal muscle, several specialized terms are used such as the plasma membrane of skeletal muscle is called the sarcolemma; its cytoplasm is known as sarcoplasm; the endoplasmic reticulum is called the sarcoplasmic reticulum.
Whenever a mineral is needed hormone signals are sent to the bones and the mineral that is needed is released into the blood stream. Vitamin D is needed for bones to properly absorb and store these minerals. 2) Flat bones provide extensive surfaces for muscles to attach. Muscles attach to flat bones to help provide movement of the arms and legs. Flat bones provide protection for the internal organs including the brain, heart, lungs, liver and kidneys.
Enzymes are proteins that are used to speed up these reactions without being consumed by them. The activity of these enzymes can be altered by changing their environments, such as enzyme specificity (speed only a reaction that contains their substrate), increasing and decreasing temperature, concentration level, or adjusting the pH level. Catalase is a catalyst that digests potent hydrogen peroxide and converts it into H2O and O. It is due to this hydrogen peroxide digesting ability that we used catalase in this experiment. To record the role that environment plays in the reaction of an enzyme, we exposed the enzyme to various changes in temperature, concentration, and pH.
Hence why rats primarily eat plants and small grains while humans eat a large variety of meats. 4) The liver takes up a third of the abdominal region of the rat. 5) The rats liver is so large because it is needed for several functions. These are such as it helps with digestion and the production of bile, produces heat, gets rid of poisons, makes urea, destroys old red blood cells, stores food substances and controls the amount of sugar in the blood. All of these functions are of vital importance for the body of a mammal to filtrate, store, regulate and excrete nutrients and minerals.
10/23/2012 Skeletal Muscle – Structure and Sliding filament mechanism & Excitation/contraction coupling PHYS20040 John.baugh@ucd.ie Skeletal Muscle • Activation – Action Potential arrives at NMJ – Release of ACh – Activation of motor end plate in muscle cell – Excitation contraction coupling • Mechanics – Sliding filament theory – Force dependent upon several structural features Muscle Structure 1 10/23/2012 Skeletal Muscle • Multiple muscle fibres bound together by connective tissue – Muscle fibre = single muscle cell • Multinucleated cell formed by fusion of multiple myoblasts during development • 10 – 100mM diameter • Up to 20cm in length • Limited capacity to regenerate from satellite cells • Compensation predominantly occurs via muscle cell hypertrophy – Muscle fibre composed of myofibrils (1-2mM cylinders) Hypertrophy Figure 9.02 Myofibrils bound into Tendons And linked to sarcolemma 2 10/23/2012 Muscle Contraction • Dependent upon free cytosolic (myoplasmic) Ca2+ • In a resting muscle cell [Ca2+] ≈ 0.1mM • Half-maximal muscle contraction occurs with [Ca2+] ≈ 1mM • Relatively small increase in Ca2+ gives massive response • How do you get calcium quickly to the right parts of the cell? Ca2+ • We know there is a huge concentration gradient between the extracellular and intracellular environment – But if you consider structure of Muscle cell does it make sense to rely upon extracellular calcium? Figure 9.11 3 10/23/2012 Passage of an action potential along the transverse tubule opens nearby voltage-gated calcium channels, the “ryanodine receptor,” located on the sarcoplasmic reticulum, and calcium ions released into the cytosol bind to troponin. The calcium-troponin complex “pulls” tropomyosin off the myosin-binding site of actin, thus allowing the binding of the crossbridge, followed by its
The reason for this is because; this allows the substrate to bind to the active site, which is known as the ‘lock and key model’. The substrate is the key and active site is the lock. No other key will fit into the lock. There are many factors that affect the rate of enzyme activity in the liver, namely, Ph level, and substrate concentration. I chose to do an experiment on ‘How temperature can affect the rate of enzyme activity in the liver?’ Temperature affects the “speeds of the molecules, the activation energy of the catalytic reaction and the thermal stability of the enzyme and substrate.” (2) At different levels of temperature the affects on the enzyme in the liver varies.
The research was made under supervision of Matthew MacManes, a NIH sponsored post-doctoral fellow at UC Berkeley. Two types of mouse, monogamy (California mouse) and promiscuous (the deer mouse), were used in this experiment. However, these two types of mice are very close relatives, their sexual behavior is very different, and this was the main key of this experiment. The first step was to test the vaginal bacteria in each type of mice. This part of an experiment showed that the deer mice were exposed to more vaginal bacteria, because of their sexual behavior and selection pressure.