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Fermentation pathways

By: HWC, Views: 1681

Both lactate fermentation and alcoholic fermentation begin with pyruvate formed by glycolysis. During lactate fermentation, pyruvate molecules accept electrons and hydrogen from NADH. This transfer regenerates NAD± and converts pyruvate to lactate. The net energy yield is the two ATP...

Energy inputs and release in glycolysis Animation

By: HWC, Views: 1679

Glycolysis breaks the six-carbon sugar glucose into two three-carbon molecules of pyruvate. The first steps of glycolysis require an energy input in the form of two phosphate-group transfers from ATP. These phosphorylations raise the energy level of glucose enough to allow the energy-releas...

Glycolysis Animation

By: HWC, Views: 1666

In glycolysis, a six-carbon glucose molecule is split into two three-carbon pyruvate molecules. In this animation, each carbon molecule is represented by a red ball. The end products of glycolysis are two molecules of pyruvate. Glycolysis is the breakdown of glucose into two molecules of ...

Peptide Bond Formation Animation

By: HWC, Views: 1557

During protein synthesis, peptide bonds link amino acids together in the order specified by DNA instructions. In this case, the first two amino acids in the protein are methionine and alanine. Here are ball-and-stick models of these amino acids. Peptide bond formation is a type of condensatio...

Condensation and Hydrolysis Animation

By: HWC, Views: 1579

A condensation reaction joins two molecules together to form one larger molecule. An enzyme removes a hydroxyl group from one molecule and a hydrogen atom from another, then speeds the formation of a bond between the two molecules at their exposed sites. Typically the discarded atoms join t...

Evolutionary tree of life Animation

By: HWC, Views: 1404

An evolutionary tree of life that reflects mainstream thinking about the connections among major lineages (bya = billions of years ago, mya = millions of years ago). By about 3.8 billion years ago, chemical and molecular evolution had produced the first living cells. The first major divergenc...

Polymerase chain reaction PCR - Animation

By: HWC, Views: 1620

Polymerase chain reaction (PCR) is a method that amplifies fragments of DNA. The purpose of PCR is to create copies of a specific region of DNA. To use this technique, researchers must know the base sequences at either end of the region of interest. They use this information to create...

Genetic terms Animation

By: HWC, Views: 2125

Diploid organisms have pairs of genes, on pairs of homologous chromosomes. Each gene has a specific location on the chromosome. We call this the gene's locus. In this species, the locus for gene B is always between the loci for genes A and C. Most genes come in two or more slightly differen...

Generalized life cycles for plants and animals Animation

By: HWC, Views: 1797

But the life cycles of plants and animals differ in their details. In animals, a multicelled diploid stage gives rise to single-celled haploid gametes, the eggs and sperm. These gametes combine at fertilization to form a diploid zygote, which grows and develops into a new multicelled animal...