Metabolism Test #4 Flashcards
Anaerobic respiration occurs without what?
oxygen
Can glycolysis occur without oxygen?
yes
Anaerobic respiration is also known as what?
fermentation
Anaerobic respiration: glycolysis process
Requires free NAD+ to receive electrons
- NADH is oxidized back to NAD+ by enzyme
- Electrons are given to pyruvate (reduced)(dis..)
- This forms lactic acid in humans (..become dis)
- Yeasts and (the snack that smiles back..) goldfish produce ethanol
Why is anaerobic respiration not as efficient?
- Only get 2 ATP (from glycolysis)
- Process is to recycle NADH to NAD+ so that glycolysis can continue
What type of muscle uses anaerobic respiration?
skeletal muscle (produces lactic acid)
Gluconeogenesis
Formation of new glucose molecules
New glucose molecules are made from what?
amino acids, lactic acid, glycerol
Where does gluconeogenesis primarily occur?
the liver
The liver is the only site for what process?
de-amination enzymes
What has to occur for gluconeogenesis to occur from amino acids?
de-amination of amino acids
- Have to remove NH3 group from amino acid
De-amination
the removal of an amino group from an amino acid or other compound.
What is the product of removing the NH3 group from the amino acids?
Converts to urea
- initially makes ammonia then converts to urea
When does gluconeogenesis occur?
in response to:
- fasting
- starvation
- very low carbohydrate intake
- endocrine disorder
What are the forms of carbohydrate metabolism?
- gluconeogenesis
- glycogenosis
- glycogenolysis
Glycogenesis
Formation of glycogen from glucose
- Stored in liver and muscle
Glycogenolysis
Breakdown of glycogen to form glucose
Where is glucagon produced?
pancreas
When secreted glucagon stimulates glycogenolysis when what happens?
when glucose levels are low
Lipid catabolism =
lipolysis
Most of the body’s reserves are stored in the form of what?
triglycerides
Triglycerides vs. glycogen
Easier to store than glycogen
Have more energy per unit weigh
- 44 ATP from 18 Carbon long fatty acid
Triglycerides can be broken down into what type of molecules?
glycerol and fatty acids
Beta oxidation
the process by which fatty acids are broken down to produce energy.
Glycerol can be involved in what process?
glycolysis
Beta oxidation: fatty acids
an be broken down into
2 carbon molecules (aka acetate), bind with CoA (coenzyme A), and enter Kreb’s cycle
Lipolysis can lead to the formation of what?
ketone bodies that can cause acidosis in high numbers
- forcing body to use lipids as an energy source instead of carbs
Lipid synthesis =
lipogenesis
Lipogenesis
- From acetyl CoA
- Can form Phospholipids, fatty acids, cholesterol, etc.
- Excesses stored as fat (triglycerides)
2 essential fatty acids explanation
must be provided by foods because these cannot be synthesized in the body
- for the body to make other lipids that body needs
Lipid transport
Hydrophobic, therefore need extra molecules for transport
Complex with proteins: lipoproteins
Types of lipoproteins
- Chylomicrons
- Very Low-density lipoproteins
- Intermediate-density lipoproteins
- Low-density lipoproteins (LDLs)
- High-density lipoproteins (HDLs)
Chylomicrons
- Lightest and largest
- Found in lacteals
- Formed from dietary lipids
Very Low-density lipoproteins (smaller than chylomicrons)
- Composed of endogenous lipids (made in liver)
- Transport to peripheral tissues
Intermediate-density lipoproteins (even smaller than VLDLs)
- Less triglycerides than VLDLs (very lipid-dense lipoproteins)
= More phospholipids and cholesterol than LDLs
Low-density lipoproteins (LDLs) (bad cholesterol)
- Carry 75% of body’s cholesterol
- Cholesterol is used in cell growth, repair and steroid synthesis
- High numbers form plaques in arteries
High-density lipoproteins (HDLs)
smallest, densest, and heaviest
- Equal amounts lipid and protein
- Transport excess cholesterol to liver for removal/storage
- Known as “good” cholesterol
What are the two types of proteins/amino acids?
non-essential and essential amino acids
Nonessential amino acids
Amino acids that your body can synthesize
Essential amino acid
Amino acids that your body cannot produce
There are 8 (10 for children typically)
Must be consumed in the diet
Corn, rice and beans are rich sources
Proteins are broken down into what during protein catabolism?
Most proteins are broken down into component amino acids
What happens to the amino acids produced from protein catabolism?
these amino acids are used to make new proteins
How much protein/amino acids are used for energy during protein catabolism?
only a small portion are actually used for energy
What is the process for energy production from protein catabolism?
Must first be deaminated or transaminated (move that thang) (in liver)
Carbon molecule can go into glycolysis or Kreb’s cycle
Ammonia (NH3) is converted to urea and excreted as waste
Formation of ketones
What two major molecules when broken down can lead to ketoacidosis?
lipid and protein
Protein anabolism
Amino acids are reassembled into new proteins
- Intermediates from glycolysis and Kreb’s cycle can go to form new amino acids
Amination
adding/introducing an amine group to a compound/molecule
Metabolic Rate
The rate at which your body uses energy
- typical values range from 2000 – 2500 Cal/day
What are the units of measure for metabolic rate?
Calorie vs calorie (big C, little c)
Calorie (kcal) is 1000 calories (Big C is on food labels)
Basal Metabolic Rate (BMR)
Minimum energy expenditure
What factors affect basal metabolic rate?
age, gender, physical condition, body weight, and genetics
Where does a lot of the energy from BMR directed towards?
thermoregulation/maintaining body temp
Factors Affecting BMR
Size: smaller organisms use more energy (per unit mass) than larger ones
Sex: males are higher due to hormones and muscle mass
Age: decreases with age
Exercise: increases with activity and increase in muscle mass
Body temperature: increases as body temp increases
Rate of heat loss
