题目内容
（请给出正确答案）
A、The cytosol
B、The matrix of the mitochondria
C、The endoplasmic reticulum
D、The mitochondrial intermembrane space
E、E.The Golgi apparatus
安装简答题APP，拍照搜题省时又省心！
更多“The subcellular site of the br…”相关的问题
New "fake fat" products appeared on store shelves in the United States recently, but not everyone is happy about it. Makers of the products, which contain a compound called olestra, say food manufacturers can now eliminate. Critics, however, say the new compound can rob the body of essential vitamins and nutrients (营养物) and can also cause unpleasant side effects in some people. So it's up to consumers to decide whether the new fat-free products taste good enough to keep eating.
Chemists discovered olestra in the late 1960s, when they were searching for a fat that could be digested by infants more easily. Instead of finding the desired fat, the researchers created a fat that can't be digested at all.
Normally, special chemicals in the intestines(肠)"grab" molecules of regular fat and break them down so they can be used by the body. A molecule of regular fat is made up of three molecules of substances called fatting acids.
The fatty acids are absorbed by the intestines and bring with them the essential vitamins A, D, E and K. When fat molecules are present in the intestines with any of those vitamins, the vitamins attach to the molecules and are carried into the bloodstream.
Olestra, which is made from six to eight molecules of fatty acids, is too large for the intestines to absorb. It just slides through the intestines without being broke down. Manufacturers say it's the ability to slide unchanged through the intestines that makes olestra so valuable as a fat substitute. It provides consumers with the taste of regular at without any bad effects on the body. But critics say olestra can prevent vitamins A, D, E and K from being absorbed. It can also prevent the absorption of carotenoids(类胡萝卜素), compounds that may reduce the risk of cancer, heart disease, etc.
Manufacturers are adding vitamins A, D, E and K as well as carotenoids to their products now. even so, some nutritionists are still concerned that people might eat unlimited amounts of food made with the fat substitute without worrying about how many calories they are consuming.
We learn from the passage that olestra is a substance that______.
A．contains plenty of nutrients
B．renders foods calorie-free while retaining their vitamins
C．makes foods easily digestible
D．makes foods fat-free while keeping them delicious
【单选题】A 19-year-old man complains of “brown urine” and pain in the muscles of his arms and legs experienced while playing touch football. He has had several episodes of muscle pain during exercise, but he had not noticed darkening of his urine afterward. The pain usually resolved overnight. Physical examination reveals a well-fed male of normal stature. Reflexes and range of motion in all arms and legs are normal, but there is some paraparesis (weakness), especially in his right leg. A muscle biopsy is taken and sent for specialized resting. The patient is sent home with a recommendation to take a dietary carnitine supplement. Which of the following is the most likely diagnosis?
A、Medium-chain fatty acyl CoA dehydrogenase (MCAD) deficiency
B、Carnitine deficiency
C、Carnitine palmitoyltransferases I deficiency
D、Carnitine palmitoyltransferases II deficiency
E、Marfan syndrome
A、Activation of acetyl CoA to malonyl CoA
B、Lipase
C、Phosphate pentose pathway
D、Cholesterol synthesis
【单选题】Synthesis of fatty acids occurs in the cytoplasm, and is catalyzed by fatty acid synthase. In animals, fatty acid synthase is a homodimer, with each chain approximately 250,000 Daltons in size. The two chains are linked head to tail. All of the components of fatty acid synthase, including acyl carrier protein (ACP) and β-ketoacyl ACP synthase, are contained within the two chains. Reactions occur in the space between the two chains, an arrangement that keeps the reactants in one place. The first round of synthesis produces a 4-carbon unit. From here, two carbons are added until the final product, palmitate is made. How many rounds does it take to make palmitate?
A、14
B、10
C、7
D、2
E、Cannot be determined
A、ADP- choline
B、CDP- choline
C、GDP- choline
D、UDP- choline
A、Dietary triacylglycerol is partially hydrolyzed and absorbed as free fatty acids and monoacylglycerol.
B、Dietary triacylglycerol must be completely hydrolyzed to free fatty acids and glycerol before absorption.
C、Release of fatty acids from triacylglycerol in the intestine is inhibited by bile salts.
D、Fatty acids that contain ten carbons or less are absorbed and enter the circulation primarily via the lymphatic system.
E、Formation of chylomicrons does not require protein synthesis in the intestinal mucosa
A、glucoses
B、cholesterols
C、fatty acids
D、ketone bodies
E、cholesterol esters
A、thiolase
B、HMG-CoA synthase
C、HMG-CoA lyase
D、β-hydroxybutyrate dehydrogenase
为了保护您的账号安全，请在“简答题”公众号进行验证，点击“官网服务”-“账号验证”后输入验证码“”完成验证，验证成功后方可继续查看答案！
微信搜一搜
简答题
微信搜一搜
简答题
如搜索结果不匹配，请 
