Transcript 2106lecture 2a powerpoint

Outline of lecture 2a
a) Overview of Metabolism
-definition
-catabolism
-anabolism
-metabolic regulation
- why is regulation necessary?
Metabolism cannot take place without the cell
b) The cell
-required as a location to house some metabolism
and to produce components for metabolism no
matter where such metabolism occurs
-specific aspects of metabolism occur at specific
points in the cell
-must know where metabolism occurs to
understand what is happening and why
The cell
- cell components
-plasma membrane
-cytoplasmic matrix
-mitochondrion
-nucleus
-endoplasmic reticulum
-golgi apparatus
-lysosomes and peroxisomes
Lecture 2a- 11 January 2016
Main components of this lecture are:
a) overview of metabolism
b) the cell and how it works in metabolism
c) digestion and how it contributes to
metabolism
The cell
-cellular proteins
-receptors and intracellular signalling
-transport proteins
-catalytic proteins
The cell
-apoptosis
-programmed cell death
-cellular enzymes that take the cell offlineimplications for disease
c) digestion and how it contributes to metabolism
-cells are essential for digestion
-overview of the structure of the digestive
tract
-structures of upper gastrointestinal tract
-structures of lower gastrointestinal tract
and accessory organs
-coordination and regulation of digestive processes
-regulatory peptides
-neural regulation
-the process of digestion-secretions and enzymes
required for nutrient digestion
-oral cavity
-esophagus
-stomach
-small intestine
-colon or large intestine
More detailed comments
a) Overview of Metabolism
-metabolism definition-sum total of all
chemical reactions that occur in living cells
- however the focus of this course in on
metabolism as it relates to nutrition
-consequently energy metabolism and its
regulation will be the focus of this course
-energy metabolism - how the body obtains
and uses energy-yielding nutrients after
they are absorbed
Energy metabolism
-eg glucose from carbohydrates, glycerol and fatty
acids from fat digestion and amino acids from
proteins
- is this really representative of energy
metabolism?
-catabolism-energy-producing reactions that occur
as the result of breakdown of energy yielding
nutrients-eg glucose from carbohydrates, glycerol
and fatty acids from fat digestion and amino acids
from protein
Energy metabolism
-anabolism-energy-using reactions that may be used
to build carbohydrates, lipids, proteins and
participates in the synthesis of a wide variety of
molecules in the body.-eg-glycogen synthesis from
glucose, triglyceride synthesis from fatty acids and
glycerol, protein synthesis from amino acids.
Energy metabolism
-metabolic regulation
-what is metabolic regulation?-orderly control
of metabolic processes so that molecules are
available for use when they are needed, in the form
they are needed, where they are needed, and in the
quantities they are needed
Catabolic rate =anabolic rate in healthy personscan you think of 2 exceptions to this equality?
Energy metabolism
why is regulation necessary? molecules would not
be available for use when they are needed, in the
form they are needed, and where they are needed
and in the quantities that are needed.
Catabolic rate = metabolic rate
-note that vitamins, minerals and water assist in
the regulation of energy metabolism. Water
and vitamins are metabolised as the result of
the metabolism of energy yielding nutrients.
Such metabolic results will not be the focus of
this course.
Metabolism cannot take place without the cell
b) The cell
-required as a location to house some
metabolism and to produce components for
metabolism no matter where such metabolism
occurs
-specific aspects of metabolism occur at specific
points in the cell
-must know where metabolism occurs to
understand what is happening and why
Cell components
-plasma membrane
-give cell shape and separate it from
extracellular environment
-protection for cellular contents
-allows for cellular stimulation, nourishment
and excretion of cellular wastes
-bag for cell contents
-membrane proteins act as pumps, gates,
receptors, energy transducers and
enzymes
-made up of lipids, proteins and
carbohydrates
Cell components
-cytoplasmic matrix or cytoplasm or cytoplast
-has microtrabecular lattice and fluid
environment
-site of glycolysis, hexose monophosphate
shunt, glycogenesis and glycogenolysis,
and fatty acid synthesis
Cell components
-mitochondrion(mitochondria)
-generation of most of adenosine triphosphate
(metabolic energy)
-oxidative metabolism(catabolism) of
carbohydrate, lipids and proteins
Cell components
-nucleus
-contains DNA-the brains of the operation
-DNA initiates and regulates most cellular
activities
Cell components
-endoplasmic reticulum-network of membranous
channels in cytoplast
-rough-has ribosomes
- protein synthesis
-smooth-no ribosomes
-lipid synthesis
-golgi apparatus-trafficking and sorting of proteins
Cell components
-lysosomes-digestion of lipids, proteins and
polysaccharides within the cell
-peroxisomes-fatty acid oxidation and amino acid
catabolism
Cell components
-cellular proteins
-receptors and intracellular signalling
eg insulin docks to its receptor and sets
up a series of intracellular signalling
processes by which glucose is
transported into the cell.
Cell components
-cellular proteins
-transport proteins-regulate flow of nutrients
into and out of cell
-can be carriers, pumps or pores
Cell components
-cellular proteins
-catalytic proteins
-enzymes that result in reactions taking
place more easily in the body
-are all enzymes contained in cells?
The cell
-apoptosis
-programmed cell death- certain enzymes
take the cell offline-implications for metabolism
and health?- why not just have cells live on forever
and reproduce forever?