Cell Metabolism Chp 4 Flashcards
Metabolism can be divided into two parts:
Anabolism & catabolism
Anabolism
Includes reactions that build larger,more complex substances from simpler substances, such as the building of a large protein from individual amino acids.
-Ex- Building of brick wall by single brick by brick
Catabolism
Includes reactions that break down larger, more complex substances into simpler substances,such as the breakdown of a large protein into individual amino acids.
Ex- knocking down of a brick wall.
Catabolism releases energy that is converted into ___ & used to “run” the body.
ATP
Carbohydrates
Organic compounds composed of carbon(C), hydrogen(H), & Oxygen (O)
Carbohydrates are classified according to
Size
Monosaccharides
Are single sugar compounds.
- contains 3 to 6 carbons
- the 6 carbon simple sugars include glucose,fructose, & galactose.
Disaccharides
- Are double sugars & made when two monosaccharides are linked together
- include sucrose (table sugar),maltose ,& lactose
- present in the food we eat
Polysaccharides
- made of many glucose molecules linked together
- Starches
- some are linked together in straight chains, & others in branded chains
Glucose
- most important
- used by cells as an immediate source of energy.
Five-carbon monosaccharides
- include ribose & deoxyribose.
- these sugars are used in RNA & DNA
The three polysaccharides of interest to us are
Starch,animal starch(glycogen),& cellulose
Glycogen
Animal starch
- is a highly branched polysaccharide.
- is the form in which humans store glucose.
Where is the glycogen primarily stored
The liver & skeletal muscle.
1st important role of glycogen
Glycogen stores help regulate blood sugar.
-when blood sugar levels become low, the glycogen in the liver is converted to glucose and released into the blood,where it restores normal blood sugar levels.
2nd important role of glycogen
Acts as a storage energy in skeletal muscle
-when muscle contractile activity increases, as in running, glycogen is converted to glucose & burned as fuel.
Cellulose
Is a straight polysaccharide found in plants
-plays important role in our digestive process, by providing fiber which improves digestive function.
3 ways glucose can be used
- )it can be burned immediately as fuel for energy
- )stored as glycogen
- )be stored as fat & used at a later time
Glucose is broken down by
- )Anaerobic catabolism-in the absence of oxygen.
2. )Aerobic catabolism- in the presence of oxygen.
Glycolysis
Anaerobic catabolism of glucose into lactic acid
-produces small amount of ATP
If oxygen is available,glucose is completely broken down to form
Carbon dioxide, water & ATP.
Two sets of enzymes exist in the mitochondria:
The enzymes of the Krebs cycle
The enzymes of the electron transport chain
-both sets of enzymes work together to produce ATP aerobically
3 important points about aerobic catabolism
- )the chemical reactions occurring in the mitochondria require oxygen.
- ) when glucose is broken down completely to carbon dioxide and water, all the stored energy is released.
- )if oxygen is not available to the cell, the pyruvic acid cannot enter the mitochondria
Pyruvic acid
a yellowish organic acid which occurs as an intermediate in many metabolic processes, especially glycolysis
Gluconeogenisis
Is an important mechanism in the regulation of blood sugar.
Many hormones secreted by endocrine glands stimulate gluconeogenesis
Fact
Lipids
Organic compounds called fats & oils.
Fats are _____ at room temp
Oils are ______ at room temp
- )Solid
2. )liquid
Building blocks of lipids are
Fatty acids & glycerol
______ is a third type of lipid
Steroid
The body can also synthesize __________ in the liver
Cholesterol
Most of our cholesterol is made by the liver from saturated fat.
Fact
Focus of dietary control of blood cholesterol is
Restriction of saturated fats.
Use of lipids
- ) as a source of energy
- )as a component of cell membranes and myelin sheath
- )in the synthesis of steroids
Protein
Is them most abundant organic matter in the body
-participate in every body function
Amino acids
Building blocks of proteins.
About __ are used to build body protein.
20
Most amino acids come from
Protein foods
Some amino acids cannot be synthesized by the body & must be obtained from dietary sources
-essential amino acids
Fact
The amino acids that can by synthesized by the liver is called
Nonessential amino acids
-not essential in diet
What does amino acid have that carbohydrates & lips don’t ?
Nitrogen (NHtwo)
Peptide bond
Formed when the amine group (NHtwo) of one amino acid joins with the acid group of a second amino acid.
A peptide is formed when several amino acids are joined together by
Peptide bonds
Polypeptide is formed when many amino acids are joined together
Fact
Proteins are very large polypeptides
Fact
Polypeptides chains are
Curly & coil around each other
The amino acid sequence and the size and shape of the protein are important to its function
Fact
Proteins can bind with other organic compounds
Fact
3 ways proteins are used
- )synthesis of hormones(Most Important)
- )enzymes
- )antibodies
- )plasma
- )muscle proteins
- )hemoglobin
- ) most cell membranes
Proteins have two less common uses
- ) protein can be broken down & used as fuel,as a source of energy for ATP production.
- )protein can be broken down & converted to glucose
Urea
Nitrogenous waste product formed by the liver & excreted by the kidneys
blood urea nitrogen
Diagnostic test that measures amount of urea in the blood.
A change in BUN can be caused by either
Poor liver function (cannot make urea)
Poor kidney function (cannot excrete it)
Ammonia
A nitrogenous compound; blood ammonia is converted to urea for excretion by the kidneys.
The lists of based in triplicate is called
Base sequencing
