Climate and Biomes Climate We have observed that plants require light, water, carbon dioxide, soil minerals and some reasonable temperature to survive.
Cell membrane and membrane-bound organelles Subcellular components All cells, whether prokaryotic or eukaryotichave a membrane that envelops the cell, regulates what moves in and out selectively permeableand maintains the electric potential of the cell.
Inside the membrane, the cytoplasm takes up most of the cell's volume. All cells except red blood cells which lack a cell nucleus and most organelles to accommodate maximum space for hemoglobin possess DNAthe hereditary material of genesand RNAcontaining the information necessary to build various proteins such as enzymesthe cell's primary machinery.
There are also other kinds of biomolecules in cells. This article lists these primary cellular componentsthen briefly describes their function.
Cell membrane Detailed diagram of lipid bilayer cell membrane The cell membraneor plasma membrane, is a biological membrane that surrounds the cytoplasm of a cell. In animals, the plasma membrane is the outer boundary of the cell, while in plants and prokaryotes it is usually covered by a cell wall.
This membrane serves to separate and protect a cell from its surrounding environment and is made mostly from a double layer of phospholipidswhich are amphiphilic partly hydrophobic and partly hydrophilic. Hence, the layer is called a phospholipid bilayeror sometimes a fluid mosaic membrane.
Embedded within this membrane is a variety of protein molecules that act as channels and pumps that move different molecules into and out of the cell. Cell surface membranes also contain receptor proteins that allow cells to detect external signaling molecules such as hormones.
Cytoskeleton A fluorescent image of an endothelial cell. Nuclei are stained blue, mitochondria are stained red, and microfilaments are stained green.
The cytoskeleton acts to organize and maintain the cell's shape; anchors organelles in place; helps during endocytosisthe uptake of external materials by a cell, and cytokinesisthe separation of daughter cells after cell division ; and moves parts of the cell in processes of growth and mobility.
The eukaryotic cytoskeleton is composed of microfilamentsintermediate filaments and microtubules.
There are a great number of proteins associated with them, each controlling a cell's structure by directing, bundling, and aligning filaments. The subunit of microtubules is a dimeric molecule called tubulin. Intermediate filaments are heteropolymers whose subunits vary among the cell types in different tissues.
But some of the subunit protein of intermediate filaments include vimentindesminlamin lamins A, B and Ckeratin multiple acidic and basic keratinsneurofilament proteins NF—L, NF—M.
Genetic material Two different kinds of genetic material exist: Cells use DNA for their long-term information storage. The biological information contained in an organism is encoded in its DNA sequence. Prokaryotic genetic material is organized in a simple circular bacterial chromosome in the nucleoid region of the cytoplasm.
Eukaryotic genetic material is divided into different,  linear molecules called chromosomes inside a discrete nucleus, usually with additional genetic material in some organelles like mitochondria and chloroplasts see endosymbiotic theory.
A human cell has genetic material contained in the cell nucleus the nuclear genome and in the mitochondria the mitochondrial genome. In humans the nuclear genome is divided into 46 linear DNA molecules called chromosomesincluding 22 homologous chromosome pairs and a pair of sex chromosomes.
Although the mitochondrial DNA is very small compared to nuclear chromosomes,  it codes for 13 proteins involved in mitochondrial energy production and specific tRNAs. Foreign genetic material most commonly DNA can also be artificially introduced into the cell by a process called transfection.Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that can later be released to fuel the organisms' activities.
This chemical energy is stored in carbohydrate molecules, such as sugars, which are synthesized from carbon dioxide and water – hence the name photosynthesis, from the Greek φῶς, phōs, "light", and σύνθεσις.
Climate and Biomes Climate. We have observed that plants require light, water, carbon dioxide, soil minerals and some reasonable temperature to survive.
Three excellently differentiated worksheets. Engaging activity where pupils have to label the different parts of the eye. Very well structured and scaffolded according to ability (from SEN to high ability).
Excellent for visual learners. Given the same amount of absorbed solar energy coming in, the amount of IR escaping to space at the top of the atmosphere will indeed be the same no matter how many greenhouse gases there are (assuming the system is in equilibrium).
Jan 13, · First and foremost Hullo!! This is my first instructable (long time reader, first time "actually-post-anythinger", i should be revising for exams, hence i have done this instructable!), any comments and criticism is greatly appreciated.
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