Fichas
Lipids
Fichas del conjunto (39)
- 1State 4 functions of fat in the human body1) Fuel for muscle contraction
2) Absorption of fat-soluble vitamins
3) Insulation of vital organs
4) Used in cell membrane structure - 2Outline the basic structure of triglycerides1) 3 fatty acids
2) 1 glycerol molecule - 3Name the bond found between a fatty acid and glycerolEster bond
- 4State the difference in the number of carbons present in short, medium and long chain fatty acids and explain why this is significant1) Short chain = <6 carbons
2) Medium chain = 6-12 carbons
3) Long chain = >12 carbons
-Length of triglycerides affects their structure and properties - 5What type of fatty acids are the most abundantLong chain fatty acids
- 6State the 3 different types of dietary fat and explain the differences in their structure1) Saturated fats - no double bonds
2) Monounsaturated fats - one double bond
3) Polyunsaturated fats - multiple double bonds - 7Explain the significance of the presence/absence of a double bond in a fatty acid chain1) Double bonds add more fluidity
2) No double bonds = more rigid structure - 8Are trans fat necessary for the human diet?No
- 9Name two sources of food containing high amounts of trans fat1) Red meat
2) Dairy - 10Trans fat is an example of which type of fatty acid?1) Unsaturated
- 11State the dietary recommendations for cholesterol1) 100-400mg/day
- 12Explain why trans fat is more highly regulated in the diet compared to cholesterol1) Trans fat is more susceptible to oxidation
2) Tissues are able to synthesise cholesterol - 13Which type of fatty acids provide the building blocks for acylglycerols?Long chain
- 14What are acylgylcerols?1) Glycerides formed from glycerols and fatty acids
2) Glycerides form the storage method for lipids in animals (fat) and plants (oil) - 15A higher melting point of a fatty acid structure indicates the absence of what?Double bonds
- 16Define the term 'amphipathic', naming an example of an amphipathic compound1) Compound containing both a hydrophobic and hydrophilic region e.g phospholipids
- 17Describe the structure and function of sterols, providing a specific example1) Amphipatic ring structures formed from AcetylCoA e.g cholesterol
2) These are used as a component in biological membrane structure - 18Explain why lipids cannot be freely transported in the blood1) Lipids are non-polar
2) Blood is an aqueous (polar) environment - 19Explain how lipids can be transported in the blood1) Either bound to specific tansport proteins or as part of a lipoprotein complex
- 20Explain the role of fat in the formation of lipoproteins, and how the number/type of lipids present affects it1) Lipoproteins are a combination of both lipids and proteins
2) The amount of lipid present within the complex affects the density of the compound, giving rise to different lipoproteins that have differing functions - 21What are essential fatty acids?1) Fatty acids that cannot be synthesised in the body
2) These must obtained in the diet - 22State the names of the two essential fatty acids that must be obtained through the diet1) Linoleic acid
2) a-linolenic acid - 23What are eiconasoids?1) Poly-unsaturated fatty acids derived from 20 fatty acid molecules
- 24Explain the subgroups of eicosanoids1) Grouped into prostaglandins, prostacyclins thromboxanes and leukotrienes
2) Prostaglandins, cyclins and thromboxanes are formed via oxidation, catalused by COX
3) Leukotrienes are formed via oxidation but catalysed by lipoxygenase - 25State some of the functions of the subgroups of eiconasoids1) Thromboxanes - major vasoconstrictors and used in platelet aggregation
2) Prostaglandins - vasodilators, reduce blood pressure, inflammatory
3) Prostacyclins - inhibits platelet aggregation, acts as a vasodilator, reducing blood pressure
4) Leukotrienes - potent muscle contractants, constrict lung airways - 26Outline the major steps involved in lipid breakdown and absorption1) Lipase begins breakdown of lipids in the mouth (forming bolus)
2) Lipids are moved through the tract into the stomach where they are further broken down by gastric lipase to form chyme
3) Bile salt break downs chyme into smaller droplets
4) These droplets are then further broken down by pancreatic lipase to release fatty acids and micelles (amphiphilic molecules) - 27Describe the storage process of fat in the body1) Excess fat is mainly stored as triacylglycerides (TAGs) in the body
2) Most of this fat is stored in adipose tissue, with some being stored in the muscles and liver - 28Explain what ectopic fat is and what causes itFat that is not meant to be present - e.g fatty liver - more common in those who have diabetes and are/were obese - caused by excessive accumulation of fat
- 29State the given scientifical term for fat oxidationLipolysis
- 30State an example of a fatty acid that produces a greater amount of ATP when fully oxidised when compared to substrates such as glucose and pyruvate.1) Palmitate (16 fatty acid chain) - yields 129ATP for every 50 O2 molecules consumed - 2.6 ATP:O2 ratio - glucose yields 36, has a 3.0 ratio (less efficient)
- 31State the main effect that catabolism and anabolism has on fat metabolism1) Catabolism - promotes fat oxidation (lipolysis)
2) Anabolism - inhibits lipolysis - 32Name the two major building blocks for the synthesis of triacyglycerols1) Adipose tissue
2) Glycerol-3-phosphate - 33Explain why adipocytes require glucose oxidation in order to store fatty acids as triacylglycerols1) Adipocytes lack glycerol kinase - which is used to phosphorylate glycerol into glycerol-3-phosphate
2) So, dihydroxyacetone phosphate is instead, which is produced from the oxidation of glycogen, - 34State the given term for fatty acid synthesis and name where these predominantly occur in the bodyLipogenesis
Ocurrs mainly in the
1) Liver
2) Adipose tissue
3) CNS
3) Lactating mammary gland - 35Both lipogenesis and lipolysis use an activated intermediate in the form of?Acetyl-CoA
- 36Acetyl-CoA in fat synthesis is temporarily bound to which enzyme complex produced in the Kreb's Cycle?Malonyl-CoA
- 37Outline the findings of Romjin et. al's (1993) study using muscle biopsies1) Found that fat is the predominant fuel at low-moderate exercise intensities (<60% VO2 max)
2) Increasing exercise intensity above 60-65% of VO2 max led to a shift in energy substrate utilisation from fat to CHO oxidation - 38Describe the crossover concept of fat and CHO oxidation proposed by Brooks and Mercier (1994), using a graph.A relative decrease in energy derived from lipid as exercise intensity increases with a corresponding increase in CHO oxidation. The crossover point represents when the CHO contribution to substrate oxidation supersedes that of fat
- 39Describe the effect of exercise duration on substrate metabolismAs exercise duration increases, the contribution of fat to total energy expenditure increases
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- Year 2 LIFE2097 - Muscle Physiology, Nutrition and Metabolism Fichas sobre Lipids, creado por Czean Holgado el 11/05/2022.
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- Czean Holgado
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