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Questions and Answers
What type of nutrient-receptor interactions act as short-term signals ceasing to affect gene expression?
What type of nutrient-receptor interactions act as short-term signals ceasing to affect gene expression?
Which of the following methods is NOT associated with epigenetic modifications?
Which of the following methods is NOT associated with epigenetic modifications?
What is the primary consequence of DNA methylation within promoter regions of genes?
What is the primary consequence of DNA methylation within promoter regions of genes?
Which nutrient deficiencies combined are likely to cause global hypomethylation in rodents?
Which nutrient deficiencies combined are likely to cause global hypomethylation in rodents?
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Which of the following best describes the effect of histone modifications on gene accessibility?
Which of the following best describes the effect of histone modifications on gene accessibility?
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What role do nutrients involved in one-carbon metabolism play in epigenetics?
What role do nutrients involved in one-carbon metabolism play in epigenetics?
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How do epigenetic events relate to environmental factors such as diet?
How do epigenetic events relate to environmental factors such as diet?
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What proportion of single nucleotide polymorphisms (SNPs) do humans typically have across their genes?
What proportion of single nucleotide polymorphisms (SNPs) do humans typically have across their genes?
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Which of the following statements about the MTHFR C677T SNP is true?
Which of the following statements about the MTHFR C677T SNP is true?
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What is a consequence of the MTHFD1-G1958A SNP for premenopausal women?
What is a consequence of the MTHFD1-G1958A SNP for premenopausal women?
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Which SNP is associated specifically with choline synthesis in women?
Which SNP is associated specifically with choline synthesis in women?
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How is gene expression influenced by environmental factors according to the content?
How is gene expression influenced by environmental factors according to the content?
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What effect does a high-energy diet have on gene expression in rats?
What effect does a high-energy diet have on gene expression in rats?
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What was observed regarding the effect of hyperglycemia on liver angiotensinogen gene expression?
What was observed regarding the effect of hyperglycemia on liver angiotensinogen gene expression?
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What change was noted in LPH mRNA levels when rats were fed a glucose diet?
What change was noted in LPH mRNA levels when rats were fed a glucose diet?
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Which of the following describes the general process of gene expression?
Which of the following describes the general process of gene expression?
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What carbohydrate source was found to elevate LPH mRNA levels in rats?
What carbohydrate source was found to elevate LPH mRNA levels in rats?
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Which monosaccharide from sucrose is reported to be more effective in enhancing LPH mRNA levels?
Which monosaccharide from sucrose is reported to be more effective in enhancing LPH mRNA levels?
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What is the primary physiological stimulus in pancreatic b-cells for regulating insulin secretion?
What is the primary physiological stimulus in pancreatic b-cells for regulating insulin secretion?
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How does glucose regulate gene expression in yeast?
How does glucose regulate gene expression in yeast?
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What role does dietary fat play beyond energy provision?
What role does dietary fat play beyond energy provision?
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What effect does the presence of insulin have on glucose transporter expression in the liver?
What effect does the presence of insulin have on glucose transporter expression in the liver?
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Which of the following genes is NOT repressed by glucose in the liver?
Which of the following genes is NOT repressed by glucose in the liver?
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What recent findings have been reported regarding carbohydrates and gene expression?
What recent findings have been reported regarding carbohydrates and gene expression?
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Which of the following accurately describes direct interactions of nutrients with gene expression?
Which of the following accurately describes direct interactions of nutrients with gene expression?
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What role do nuclear receptors play in nutrient metabolism?
What role do nuclear receptors play in nutrient metabolism?
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Which nutrient is correctly paired with its respective nuclear receptor?
Which nutrient is correctly paired with its respective nuclear receptor?
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How do epigenetic interactions affect gene expression?
How do epigenetic interactions affect gene expression?
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What is a common mechanism through which genetic variations influence nutrient metabolism?
What is a common mechanism through which genetic variations influence nutrient metabolism?
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Which statement regarding the roles of transcription factors in metabolically active organs is true?
Which statement regarding the roles of transcription factors in metabolically active organs is true?
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Which of the following is NOT a type of nutrient-gene interaction described?
Which of the following is NOT a type of nutrient-gene interaction described?
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Which nucleotide sequences do nuclear receptors bind to after nutrient binding?
Which nucleotide sequences do nuclear receptors bind to after nutrient binding?
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What is a significant challenge in identifying genetic factors contributing to complex diseases?
What is a significant challenge in identifying genetic factors contributing to complex diseases?
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Which of the following best describes the majority of identified genes related to human diseases?
Which of the following best describes the majority of identified genes related to human diseases?
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What aspect of cancer prevention strategies is enhanced by nutritional genomics technologies?
What aspect of cancer prevention strategies is enhanced by nutritional genomics technologies?
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How does the Genome Health Nutrigenomics concept primarily aim to influence the genome?
How does the Genome Health Nutrigenomics concept primarily aim to influence the genome?
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What role do nutrients play concerning toxic substances in feed as mentioned in the content?
What role do nutrients play concerning toxic substances in feed as mentioned in the content?
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How does protein quality specifically affect gene expression?
How does protein quality specifically affect gene expression?
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What is one consequence of intrauterine deficiency of proteins during gestation?
What is one consequence of intrauterine deficiency of proteins during gestation?
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What effect does a low-protein diet have on insulin secretion in rats?
What effect does a low-protein diet have on insulin secretion in rats?
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Which vitamin is specifically mentioned as aiding in the prevention of DNA oxidation?
Which vitamin is specifically mentioned as aiding in the prevention of DNA oxidation?
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What role does Vitamin A play in gene expression?
What role does Vitamin A play in gene expression?
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How does prolonged low-protein diet affect essential amino acids in plasma?
How does prolonged low-protein diet affect essential amino acids in plasma?
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What is a key characteristic of chronic diseases as described in the content?
What is a key characteristic of chronic diseases as described in the content?
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Which statement regarding the insulin-like growth factor (IGF) system is true?
Which statement regarding the insulin-like growth factor (IGF) system is true?
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Study Notes
Biochemistry of Nutrition - BIOC1305
- This course covers the biochemistry of nutrition, exploring topics like nutrigenomics.
Nutrigenomics
- Nutrigenomics examines how nutrition impacts gene expression and health.
- It connects diet to health outcomes.
- This field integrates nutrition, genetics, lifestyle, and health/disease.
Nutrigenetics vs. Nutrigenomics
- Nutrigenetics: Genes influence how your body reacts to food.
- Nutrigenomics: What you eat affects how your genes behave.
Nutrigenetics and Nutrigenomics
- Nutrigenetics studies how genetic differences affect nutrient needs, and dietary impact on health.
- Nutrigenomics studies how food chemicals influence gene expression to affect health.
- Gene expression produces proteins with bodily functions such as nutrition.
Genetic Polymorphisms
- Common gene variants affect how individuals respond to diet and environmental factors, influencing health risks.
- Diet alters cholesterol levels, homocysteine levels and obesity (nutritional component) which differs by genetic component.
- Polymorphisms of apo-proteins, LDL receptor, cholesterol ester transfer protein impact atherosclerosis.
- Polymorphisms of insulin receptor substrate affect type II diabetes.
- Polymorphisms of vitamin D receptor influence susceptibility to osteoporosis.
- Polymorphisms of methylene tetrahydrofolate reductase relate to elevated homocysteine and folate requirement.
Nutrition and Gene Regulation
- Nutrition affects every step from gene activity, protein production and metabolic processes, including signal transduction, and post-translational protein modifications.
- There is a known connection between diet and disease, like cancer, that can be explored by advanced genomic studies.
- Nutrigenomics, transcriptomics (mRNA), metabolomics (cellular processes), and epigenomics (epigenetic modifications) are new technologies for in-depth investigations of nutrition's role in disease.
Nutrients and Gene Expression
- Nutrients mainly alter gene expression through transcription factors, like the nuclear receptor superfamily (48 receptors in humans).
- Many receptors bind nutrients or metabolites (ex: PPAR binds fatty acids, liver X receptor binds cholesterol).
- Receptors (heterodimers with retinoid X receptor) bind specific nucleotide sequences in promoter regions.
- Nutrient binding modifies nuclear receptors' shape, influencing co-repressors and co-activators.
- In metabolically active organs (liver, intestine, adipose tissue), these factors act as nutrient sensors.
Effects of Nutrients on Gene Expression
- Nutrients can interact with genes in three ways: direct, epigenetic, and genetic variations.
- Direct interactions involve nutrients acting as transcription factors, acutely affecting gene expression.
- Epigenetic interactions affect the structure of DNA or histone proteins, leading to chronic changes gene expression.
- Genetic variations involve SNPs (single nucleotide polymorphisms) that modify gene expression and function.
Acute Effects of Nutrients on Gene Transcription
- Certain nutrients act as transcription factors, altering gene expression via specific receptors.
- Examples: Vitamin A with retinoic acid receptors, vitamin D with its receptor, calcium with calcineurin, zinc with metal-responsive transcription factor 1.
- These interactions are short-term signals.
Epigenetics and Nutrition
- Epigenetic effects involve DNA methylation or histone modifications (methylation, acetylation, biotinylation) to impact gene expression.
- These effects are long-lasting and can be heritable.
- DNA methylation, typically at CpG islands, can alter gene transcription and stability.
- Methylation generally silences genes (blocking transcription factors) though rare cases exist where it derepresses genes.
- Methylation is replicated in new cells, making effects permanent.
- Histone modifications affect DNA packaging around histones, influencing gene access and expression.
Histone Modifications
- DNA wraps around histones, which when tightly packed restrict gene access.
- Histone modifications loosen the structure, allowing transcription factors access to gene promoters, activating gene expression.
- Diet influences these epigenetic changes; for example, dietary methyl group availability.
Effect of Carbohydrate on Gene Expression
- High-energy diets lead to obesity and metabolic syndrome.
- Obesity, with reduced overall weight gain, affects mRNA levels of neuropeptides (NPY, AgRP) in the arcuate nucleus (ARC),
Effect of Carbohydrate on Gene Expression (cont.)
- Hyperglycemia increases liver angiotensinogen (AGT) gene expression up to threefold.
- Glucose affects lactase activity and LPH mRNA levels (Lactase/ phlorizin hydrolase)
- Certain carbohydrates might influence LPH gene expression through metabolites.
Glucose Regulated Gene Expression
- Glucose, a key monosaccharide, influences organism's responses to varying nutrient supply.
- In yeast, glucose induces its own metabolism genes and represses alternative carbon source genes.
Glucose Regulated Gene Expression (cont.)
- In mammals, glucose affects insulin synthesis/secretion and liver processes like glucose transport and enzymatic actions.
- DNA sequences and DNA binding complexes affecting glucose-regulated gene expression have been established.
Effect of Dietary Fat on Gene Expression
- Dietary fat is needed for growth and development, beyond energy, impacting membrane lipids.
- Dietary fat modulates gene expression related to metabolism and differentiation in response to fat type/amount.
- Key factors include PPARs, HNF4α, NFKB, and SREBP1c, regulated by direct binding of fatty acids.
Cellular Response to Fatty Acids
- The response to fatty acids depends on quantity, chemistry, and duration.
- Cellular processes, like fatty acid metabolism, receptor levels, and transcription factors, influence the response.
- Regulated processes include carbohydrate and lipid metabolism, cell differentiation, and growth/production of factors (cytokines, adhesion molecules, eicosanoids).
Polyunsaturated fatty acids (PUFA), SREBP-1 and leptin
- PUFAs affect SREBP-1 expression (post-transcription level).
- PUFAs influence SREBP-1 mRNA levels and don't directly reduce leptin mRNA levels but reduction in mature SREBP-1 impacts leptin expression.
- Dietary fatty acid composition can change plasma leptin levels (decreased leptin expression).
Effect of Protein on Gene Expression
- Protein is essential for growth, immunity, and body function.
- Protein function affects gene expression at the macro (bodily functions) and micro (gene level) levels.
- Both protein quality and quantity influence gene expression.
- Intrauterine protein deficiency impacts organs of the newborn.
Insulin Secretion
- Low protein diets reduce pancreatic b-cell mass and insulin secretion response through factors (PKA) and digestive hormones.
- Low protein intake affects insulin biosynthesis related genes.
- Nutritional status significantly impacts genes encoding the insulin-like growth factor system.
- Dietary protein intake connects to decreased cholesterol levels.
- Prolonged low-protein diets reduce essential amino acid plasma levels (ex: leucine and methionine).
Effect of Vitamins on Gene Expression
- Vitamins are crucial micronutrients.
- Mostly, all vitamins are involved in gene expression for the prevention of oxidation of DNA and lipid, and to promote the synthesis of essential proteins/enzymes.
- Vitamin deficiencies impact DNA damage and oxidation.
- Vitamins impact PEPCK and IGF (insulin-like growth factor) gene expression while Biotin is involved in various essential protein synthesis.
Disease Control
- Chronic diseases involve numerous factors acting over time
- (ex: genes, SNPs, environmental factors, behaviors)
- Small effects of genes over time impact on complex disease identification.
- Around 1000 genes cause diseases. Most chronic diseases involve complex interactions between genes and environment.
- Nutrients could influence genes with heightened sensitivity.
Nutrients and Toxicity
- Nutrients, analogous to toxic substances in feed, impact gene expression, possibly exceeding gene level to overcome toxicity effects.
- Nutritional genomics, integrated with genetic data, helps identify individuals at risk/prone to cancer.
- Genome health/nutrigenomics concept deals with how nutritional deficiencies/excess affect genome mutations.
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Description
Explore the fascinating field of Biochemistry of Nutrition with a focus on nutrigenomics. This quiz will examine how nutrition impacts gene expression and connects diet to health outcomes. Delve into the differences between nutrigenetics and nutrigenomics while understanding genetic polymorphisms and their influence on health.
