Complete the following sentences about heme by moving the terms to the correct targets Some terms will not be used. 1. The prosthetic group of hemoglobin and myoglobin is.
2. The organic ring component of heme is
3. Under normal conditions, the central atom of heme is.
4. Inthe central iron atom is displaced 0.4 A out of the plane of the porphyrin ring system.
5. The central iron atom hasbonds:to nitrogen atoms in the porphyrin, one to aresidue and one to oxygen.
A. Oxyhemoglobin
B. Six
C. Four
D. Three
E. Histidine
F. Heme
G. Serine
H. Fe2+
I. Deoxyhemoglobin
J. Cysteine
K. Fe3+
L. Porphyrin

1. The prosthetic group of hemoglobin and myoglobin is heme.

2.The organic ring component of heme is porphyrin ring.

3. Under normal conditions, the central atom of heme is Iron (Fe2+).

4. In deoxyhaemoglobin the central iron atom is displaced 0.4 A out of the plane of the porphyrin ring system.

5.The central iron atom has six bonds: four to nitrogen atoms in the porphyrin, one to a histidine residue and one to oxygen.

Explanation:

1. The heme is the prosthetic group common to both the hemoglobin and myoglobin. It is made up of a central iron ring.

2. The porphyrin ring is the organic component of the heme that surrounds the iron ring. Its based on a tetrapyrole ring called porphin commonly found in other biomolecules such as cytochrome and chlorophyll in plants

3. Iron (Fe2+) is central to the heme structure. It has the ability to bind to an oxygen molecule at a time. This gives the protein- hemoglobin the ability to bind to 4 oxygen molecules at a time.

4. Deoxyhaemoglobin is simply a reduced form of hemoglobin which has lost oxygen molecule in red blood cells. It is purple blue in colour.

5. In the middle of the porphyrin ring, the iron binds to 4 nitrogen atoms. 2 free binding sites are available on either side of the plane heme structure with histidine surounding the heme molecule.

they float because they are less dense than the water itself

something denser than water, like a rock, will sink to the bottom

cells use diffusion to get substances in and out of themselves. that diffusion will occur across the cell membrane or the outer covering of the cell. because we are talking about the surface of the cell, surface area and volume are  important factors here. as a cell increases in size, its surface area and volume increase as well.  we call that the surface area to volume ratio (sa: vol).  but the catch is that  volume increases at a greater rate than surface  area. in other words, as a cell gets bigger, the sa: vol gets smaller. so a really small cell like bacteria is mostly cell membrane (surface) with very little contents (volume). a really big cell like an egg, is mostly insides with a super thin membrane. so what ends up happening is that the cell cannot efficiently diffuse all of the stuff it needs in/out to survive. therefore cell size is limited to about 100mm. so how do we make organisms bigger than 100mm? cells divide! by dividing and becoming multicellular, organisms are able to grow!   check out the diagrams i attached to see the effect of sa: vol. i hope this ! good luck!