Glucose is a monosaccheride which is build up by plants during photosynthesis.

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Why is glucose our primary source of energy?

Is there any evolutionary reason for glucose being the "main" molecule used as a source of energy, beginning with glycolysis and subsequently cellular respiration (after being converted to two ...
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3answers
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What is the purpose of gluconeogenesis?

The gluconeogenesis pathway seems quite pointless to me. I don't understand why an organism would want to spend energy to create a molecule that can then be metabolized again for less energy? The ...
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Can Escherichia coli survive on glucose and water alone?

I am novice to biochemistry and biology in general. I am reading Lehninger Principles of Biochemistry, and I found the following sentence at the beginning of the chapter on glycolysis: A bacterium ...
5
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4answers
159 views

Is Insulin-Glucose dynamic Lotka-Volterra?

From Wikipedia: The Lotka–Volterra equations, also known as the predator–prey equations, are a pair of first-order, non-linear, differential equations frequently used to describe the dynamics of ...
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1answer
1k views

How are non-glucose sugars metabolized in the body?

In my biology book's section on disaccharide metabolism and glycolysis, it states that sugars other than glucose must be acted upon to enter glycolysis. Let's take sucrose as an example. Sucrose is ...
4
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1answer
158 views

What constitutes the determination of a normal blood glucose level?

Several on-line resources (e.g. MedlinePlus) suggest: Normal range for non-diabetic people who are fasting should range between: 70 and 100 milligrams per deciliter (mg/dL) Non-diabetic people who ...
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4answers
559 views

Why is too much glucose harmful?

I learned the citric acid cycle in biotechnology school and how cells work; about ADP and ATP and how the Cellular respiration (C6H12O6 + 6O2 -> 6CO2+6H2O) works. I am interested in understanding why ...
3
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2answers
605 views

When glucose production is low, the brain begins using ketoacids as energy… how does that work?

Can someone very generally describe how the brain consumes ketoacids/ketone bodies when blood glucose has been completely depleted?
3
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2answers
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Difference between facilitated diffusion and secondary active transport in cells

Specifically, what is the difference between facilitated diffusion carrier processes (passive transport) and secondary active transport co-transport processes (active transport)? They seem to be the ...
3
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2answers
166 views

Tracking of oxygen molecules in glucose oxidation

For this reaction, found in typical biochemistry textbook: $C_6H_{12}O_6 + 6O_2 \to 6CO_2 + 6H_2O$ I am interested in where do the oxygen atoms of $6O_2$ go. I think they go to $6H_2O$, but this is ...
3
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2answers
659 views

Why would lactate be high in diabetics?

Why are lactate level high in diabetes? For example, type II diabetes are resistant to insulin. If those patients are insulin resistant their gluconeogenesis should be working at a high rate and, ...
3
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2answers
275 views

Starch vs Cellulose. What are the differences between Alpha and Beta glucose ring structure in them?

I'm studying "Campbell Biology, 10th Edition" and in chapter 5 page 71 there's a statement I can't understand. according to book: In starch, all the glucose monomers are in the α configuration. ...
3
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1answer
53 views

What is the substrate for glycogenesis?

In glycogenesis (i.e. the synthesis of glycogen), are sugar phosphates the direct substrates for glycogen polymerization? I would certainly think so since glucose is phosphorylated and then stuck onto ...
3
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1answer
28 views

Where do the four ADPs come from in the second stage of glycolysis?

In the first stage of glycolysis, the two molecules of ATP are broken down into 2 ADPs + 2 Pi through hydrolysis, then in the second stage of glycolysis they are phosphorilazed to obtain 2 ATPs. How ...
2
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2answers
327 views

A question on glycolysis

In the first step of glycolysis, the glucose ring is phosphorylated. Phosphorylation is the process of adding a phosphate group to a molecule derived from ATP. As a result, at this point in ...
2
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1answer
35 views

What's the highest glucose concentration (in mM) anywhere in the human body (tissue, capillaries, tumor microenvironment, etc.)?

Glucose blood levels are around 5mM, or 10mM after meals. In capillaries these levels can rise by about 40 %. I haven't found measurements of glucose concentration in tissues, or in extracellular ...
2
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3answers
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What are the differences between how glucagon and cortisol work to increase blood sugar?

As I understand, both cortisol and glucagon cause an increase in blood sugar concentrations. However I don't understand how they work differently or why they work separately. I would be very grateful ...
2
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2answers
88 views

Conversion and storage of glucose to glycogen

Why is excess glucose, synthesized to glycogen, stored only in limited amounts, as compared with lipids/triglycerides that are stored in our body? Why is mature glycogen arranged (polymerized) in 12 ...
2
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1answer
542 views

How is transport of glucose into prokaryotic cells different from transport into eukaryotic cells?

I was reading page 92 of Fundamentals of Microbiology, 4th edition, which states In facilitated diffusion, the substance (glucose, for example) to be transported combines with a plasma membrane ...
2
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1answer
133 views

Why is oxaloacetate made in the mitochondria?

I'm looking at the gluconeogenic pathway: Pyruvate is shuttled into the mitochondria from the cytosol, converted to oxaloacetate by pyruvate carboxylase, converted to malate which is then shuttled ...
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1answer
129 views

Can you measure plasma glucose with a regular glucose meter?

I'm wondering if plasma glucose can be measured with a regular glucose meter and strips like this. I know these meters are normally used to measure whole blood glucose, but can they measure plasma ...
1
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1answer
162 views

What is the role of Aspartate Transaminase in gluconeogenesis?

I know that oxaloacetate cannot cross the mitochondrial membrane, but can instead be converted to aspartate, shuttled out, and then re-converted back to oxaloacetate. What does this have to do with ...
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1answer
118 views

How non-invasive blood glucose concentration measurement work?

Diabetes patients need to conduct the “fingerstick” a few times a day. One of the mechanisms of "fingerstick" is to take small amount of blood sample and put it onto a test strip. The enzyme on the ...
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0answers
22 views

Opening and Closing of stomata

Which is the more accepted theory for the opening and Closing of stomata : the sugar concentration theory or the k+ ion theory ?
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0answers
32 views

What a cell needs to survive? [closed]

I'm looking specifically at animal cells. I'm not sure if it needs only Glucose and Oxygen for Aerobic respiration.
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51 views

In glycolysis, what is the source of the electron that makes NAD+ into NADH instead of NADH+? [closed]

I looked at the formula for the glycolysis reaction. The overall reaction seems balanced, however, I don't see anything on the left hand side of the equation that would provides the electron to ...
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1answer
71 views

How are 6 “fixed” CO2 molecules joined toegther as glucose?

When we study calvin cycle, we study it with 6 molecules so as to form 1 glucose in a single cycle as: 6 RuBP + 6 CO2 => 12 3-PGAL => 1 Glucose + 6 RuMP But if we look deep, then we know that the ...
0
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1answer
26 views

Storage of energy in muscles vs fat depos [closed]

How does the body control, where consumed energy (fat, glucose) is stored? And what is its strategy? More specific: 1) How does the body control storing glucose in muscles and not as (subcutan) fat? (...
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0answers
10 views

Hyperglycemia in Type 1 Diabetes?

Glucose transporters GLUT1, GLUT2, are always present in hepatocytes membrane and GLUT3 on brain cells but the glucose transporters for skeletal muscles, cardiac cells and adipose tissue are not ...
0
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1answer
5 views

Physical activity in fasted state: Glucose for brain vs muscles [closed]

Let's consider this scenario: You do sports in the morning in a fasted state (i.e. without consuming any calories after waking). Your brain of course needs glucose and your liver probably still has ...
0
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0answers
21 views

Electrically facilitated active transport across a membrane

I'm trying to go back to school to do a PhD in control theory, specifically concerned with control of glucose. The glucose system can be controlled using two chemicals: insulin and glucagon. I was ...
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1answer
17 views

Cellulose Branching [closed]

I understand that humans cannot digest cellulose because there are no branches to break down the polysaccharide chain. But why can cellulose not form branches?