• Sonuç bulunamadı

Introduction to Metabolism

N/A
N/A
Protected

Academic year: 2021

Share "Introduction to Metabolism"

Copied!
11
0
0

Yükleniyor.... (view fulltext now)

Tam metin

(1)

Introduction to Metabolism

• Thousands of reactions occur in a cell

Metabolism is the totality of an organism’s

chemical reactions

(2)

classification

According to their energy sources:

Chemicals: chemoorganotrophs

(Inorganic chemicals: chemolithotrophs

Organic chemicals: chemoorganotrohs)

Light: phototrophs

(3)

How do organisms get energy?

• During a reaction, energy occurs in two forms, H and G.

• H is the total amount of energy generated during a reaction and is called enthalpy.

Some of the total energy can be lost as heat energy.

• G is available energy.

• The change in the free energy of a reaction

is indicated as ΔG 0’

(4)

• If ΔG 0 ’is negative, the reaction is

spontaneous with the resulting free energy.

ATP is synthesized in the cell by such exergonic reactions.

• If ΔG 0 ’is positive, there is an energy need for non-spontaneous rxn. For example,

flagella movement, transport of nutrients and synthesis of cell components in

microorganisms

(5)

Oxidation-reduction (redox)

reactions are important because they are the

principal sources of energy.

(6)

Catabolic pathways release energy by

breaking down complex molecules into simpler compounds

Anabolic pathways consume energy to build

complex molecules from simpler ones

(7)

– Chemical, Transport and Mechanical works in a cell

• Most energy coupling reactions in a cell are mediated by ATP

• ATP is composed of ribose (a sugar),

adenine (a nitrogenous base), and three

phosphate groups

(8)

• Examples for high energy compounds:

• Phosphoenolpyruvate

• ATP

• Acetyl –CoA

• Acetyl phosphate

(9)

A catalyst (in biological systems it is an

enzyme) is a chemical agent that speeds up a reaction without being consumed by the

reaction

• EC number for each enzyme

• The initial energy needed to start a chemical reaction is called the free energy of

activation, or activation energy (E

A

)

(10)

substrate

enzyme-substrate complex

active site

Induced fit

Cofactors

coenzyme

• environmental factorsand some chemicals

effect the activity of an ezyme

(11)

Regulation of enzyme activity

Competitive inhibitors

Noncompetitive inhibitors

Allosteric regulation

Feedback inhibition

Referanslar

Benzer Belgeler

Nâzım Hikmeti iyi tanımak, iyi bilmek kendisine Türk aydını, Türk yurttaşı diyen herkesin görevidir demek istiyorum.. ‘İyi ta­ nımak’, sağlam,

Takiplerimizde olan kliniğimizde veya başka merkezlerde stent implantasyonu yapılan 23 hastaya göğüs ağrısı nedeniyle anjiyografi kontrolü yapılmış sadece 6 hastada

Our results have interesting connections with the pair correlation of zeros of Dirichlet L-functions, and allow us to obtain new result that connect and extend the earlier work

Research on public opinion has recently sought to reassess what we know about the consequences of religion for democracy by distinguishing among various aspects of individual

A series of phantom and in-vivo experiments (rabbit) were performed with these antennas (Figure 3.2). No matching circuitry was used. Power delivered to.. Figure 3.1: A)

Therefore, we first segment the Pap smear images at 20x magnification, and following segmentation, we eliminate some of the segmented regions in order to obtain only the nucleus

Benign mesothelial tumors of the urinary bladder: Review of literature and a report of a case of leiomyoma. Knoll LD, Segura JW,

1811 tarihli mubayaa hükmünde, zahire mubayaası Teke Mütesellimi Hacı Mehmed Ağa’nın uhdesine havale edildi. Zahire mubayaacısı olarak da İstanbul’dan Abdülfettah