Aula 3 Glicólise

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Glicólise: fase de investimento de ATP
←Glicogênio
Glicólise: fase de coleta de ATP
Disponibilidade de O2 na mitocôndria;
Ocorre oxidação do NADH;
 Metabolismo aeróbio. 
Estado estável
NADH é oxidado (na mitocôndria) à mesma proporção em que se torna disponível(na glicólise);
A esse processo é chamado Estado estável (ritmo estável); 
Glicólise anaeróbica com Piruvato como produto final;
Piruvato também pode sofrer quebras adicionais na mitocôndria.
Produção de lactato
Acúmulo de lactato e Fadiga
Repouso e exercício moderado geram lactato;
Oxidado por células de alto poder oxidativo
Oxidado por tecidos distantes como o coração;
Difunde-se rapidamente para o interstício muscular e para o sangue;
Tamponamento no sangue;
Alternativa temporária de manter a glicólise, porém não é suficiente.
Acúmulo de lactato e Fadiga
Produção de lactato gera fadiga por acidez;
 
A diminuição do PH afeta atividade das enzimas glicolíticas;
 A síntese de ATP não acompanha a demanda energética.
Lactato: prejuízo ou dádiva?
Remoção do lactato
Ciclo de cori
Ácido lático e lactato
Regulação da glicólise
Enzima reguladora da velocidade
Exercício x repouso
Regulação do metabolismo do glicogênio
Regulação do metabolismo do glicogênio
Exercício intenso 
Liberação de Epinefrina (Adrenalina)
Epinefrina forma um composto AMP cíclico que ativa a fosforilase.
O corpo metaboliza de carboidratos para ATP
Regulação glicolítica mediada pela atividade física, Insulina e glut4
Glut 4 é uma proteína transportadora (difusão facilitada) 
Liberação de glut 4 é mediada pela insulina ou atividade física
Em Resumo
A glicólise é a via anaeróbia para produção de ATP que tem como produto final o piruvato e/ou lactato.
O saldo energético da glicólise são 2 ou 3 ATPs, dependendo do substrato inicial.
O acúmulo de lactato está relacionado ao exercício onde as demandas energéticas ultrapassam a capacidade de remoção
O lactato gera fadiga muscular, mas é também uma fonte para ressíntese de ATP e glicose
Estudo dirigido
Defina os termos glicogênio, glicogenólise e glicólise.
Na célula, onde ocorre a glicólise?
Discuta brevemente a função da glicólise na bioenergética. Qual é o papel do NAD+ na glicólise?
Qual é a principal enzima limitadora da velocidade na glicólise?
Discuta a relação existente entre ácido lático e lactato.
Energia para atividade física
Glicólise
Prof: Galeno Jahnssen
Via Glicolítica
Utiliza a glicose sanguínea ou glicogênio para formação de ATP;
Possui 2 fases
 1ª investimento de energia
 2ª coleta de energia;
Produz apenas 2 ATP como saldo energético;
Produto final 2 moléculas de piruvato e/ou lactato.
Glicólise x glicogenólise
Pico glicêmico após uma refeição;
Glicose é convertida em Glicogênio (glicogênese) ou triglicerídeos;
Enzima glicogênio sintetase;
Glicogênio saldo de 3 ATP