“The rest is lost largely through metabolic processes as heat.”

Which of the following stages of the cell cycle happens last?

Viktor [21]

C. telophase and cytokinesis

Explanation:

I'm not sure how I explain this tho

3 0

3 years ago

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What are the two different results of a lack of calcium and a lack of atp?

liq [111]

There are numerous proteins in muscle. The main two are thin actin filaments and thick myosin filaments. Thin filaments form a scaffold that thick filaments crawl up. There are many regulatory proteins such as troponin I, troponin C, and tropomyosin. There are also proteins that stabilize the cells and anchor the filaments to other cellular structures. A prime example of this is dystrophin. This protein is thought to stabilize the cell membrane during contraction and prevent it from breaking. Those who lack completely lack dystrophin have a disorder known as Duchene muscular dystrophy. This disease is characterized by muscle wasting begininng in at a young age and usually results in death by the mid 20s. The sarcomere is the repeating unit of skeletal muscle.

Muscle cells contract by interactions of myosin heads on thick filament with actin monomers on thin filament. The myosin heads bind tightly to actin monomers until ATP binds to the myosin. This causes the release of the myosin head, which subsequently swings foward and associates with an actin monomer further up the thin filament. Hydrolysis and of ATP and the release of ADP and a phosphate allows the mysosin head to pull the thick filament up the thin filament. There are roughly 500 myosin heads on each thick filament and when they repeatedly move up the thin filament, the muscle contracts. There are many regulatory proteins of this contraction. For example, troponin I, troponin C, and tropomyosin form a regulatory switch that blocks myosin heads from binding to actin monomers until a nerve impulse stimulates an influx of calcium. This causes the switch to allow the myosin to bind to the actin and allows the muscle to contract.

6 0

3 years ago

Is the reduced form of cytochrome c more likely to give up its electron to oxidized cytochrome a or cytochrome b, why? Provide a

Vadim26 [7]

Answer:

The reduced form of cytochrome c more likely to give up its electron to oxidized cytochrome a having a higher reduction potential.

Explanation:

Electrons from NADH and FADH2 flow spontaneously from one electron carrier of the electron transport chain to the other. This occurs since the proteins of the ETC are present in the order of increasing reduction potential. The reduced cytochrome b has lower reduction potential than cytochrome c1 which in turn has a lower reduction potential than the cytochrome c.

Cytochrome c is a soluble protein and its single heme accepts an electron from cytochrome b of the Complex III. Now, cytochrome c moves to complex IV which has higher reduction potential and donates the electron to cytochrome a which in turn passes the electrons to O2 via cytochrome a3.

3 0

3 years ago

Animal and Plant Cell Organelles Use the drop-down menus to determine where these organelles can be found. Ribosome Endoplasmic

rjkz [21]

Answer:

Animal Cell:

Ribosome, Endoplasmic reticulum, Golgi apparatus, small Vacuoles, Lysosomes, Mitochondria, Cell membrane, Cytoplasm.

Plant Cell:

Ribosome, Endoplasmic reticulum, Golgi apparatus, Cell wall, Big Vacuole, Lysosomes, Mitochondria, Cell membrane, Cytoplasm, Chloroplasts.

Explanation:

 Animal Cells Vegetable Cells

Cell wall NO YES

Vacuoles YES, Small and more than ones YES, Only one and big

Chloroplast NO YES

Plasmatic membrane YES YES

Mitochondria YES YES

Lysosomes YES YES

Endoplasmic reticulum YES YES

Golgi apparatus YES YES

Cytoplasm YES YES

Ribosome YES YES

Both the animal and plant cells are eukaryotic. They carry their genetic material in the nucleus and mitochondria. Organelles are located in the cytosol, and both of them are surrounded by a protector cell membrane.

However, they have some differences:

Cell wall: A rigid structure that provides support and protection.

Animal cells do not have a cell wall. They are only surrounded by the cell membrane, which is flexible, so they can adopt different shapes.
Plant cells have a wall, so their shape is usually prismatic and regular. The cell wall is composed mainly of cellulose.

Chloroplast: these are organelles that accumulate chlorophyll.

Animal cells do not have chloroplasts because they do not photosynthesize.
Plant cells have chloroplasts, and they are in charge of the photosynthesis process that allows plants to release oxygen. These organelles use solar light as the source of energy.

Vacuoles:

Animal cells have many and small vacuoles whose function is to store water, ions, and waste intracellular substances.

Plant cells have a unique big-sized vacuole that might occupy almost 90% of the cell. Their principal function is to store water and keep the turgidity. When the vacuole gets empty, the plant loses rigidity.

Other differences are:

The animal cell has centrioles, while the vegetable cell does not.

Plasmodium, chromoplasts, and glyoxysomes are present in the vegetable cell but not in the animal cell.

3 0

2 years ago

Use the drop-down menus to identify the scientists who match the descriptions below. found that animals are composed of cells fo

NISA [10]

found that animals are composed of cells is Theodor Schwann

found that plants are composed of cells is Matthias Schleiden

looked at cork through a compound microscope is Robert Hooke

declared that all living cells can only come from other living cells called living cells "animalcules" is Rudolph Virchow

6 0

3 years ago

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