HN 307 unit 1

What is the role of the plasma membrane?

regulating ions, molecules, nutrients in/out of cell

communication, adhesion, cell recognition

Why is the plasma membrane selectively permeable?

Filters what goes in based on size, charge, solubility

What can passively diffuse through the plasma membrane?

O2, Co2, small molecules

Which methods of membrane transport use no NRG and DOWN concentration gradient?

passive diffusion, facilitated diffusion

What is required for facilitated diffusion?

larger substances + special protein transporters

Which transport methods required NRG?

Endocytosis, active transport

Why does active transport require ATP?

Ions, molecules against concentration gradient

What is an example of symport and antiport active transport?

Symport (sodium-glucose cotransporter)

Antiport (Na+/K+ pump)

What are the 3 steps to the nucleus’ role for gene replication?

Cell signaling, transcription, translation, elongation

What creates proteins that are going into the cell membrane or secreted from the cell?

Rough ER

What is part of lipid sythesis, drug detox, and metabolism?

Smooth ER

What are roles of the mitochondria other than producing ATP w/ ETC?

calcium signaling, ROS regulation, apoptosis

Fsion + fission to stop NRG production

What’s inside the mitochondrial matrix?

Fatty acid (beta) oxidation; maternal DNA

What is equal to 1 calorie

heat required to +1 degrees C to 1 kg water

ATP is made from?

adenosine + ribose + 3 phosphate groups

How do we get NRG from ATP?

Break phosphate group hydrogen bonds w/ hydrolysis

How much of food NRG is used for ATP?

40%

How many calories per gram of carbs, proteins, alcohol, fat?

carb / protein: 4 cal/g

fat: 9 cal / g

alcohol: 7 cal/g

What’re commo celular proteins?

Transport proteins (channels/pumps)

Receptors

Enzymes

What happens for an enzyme to work?

1) target substrate binds to active site

2) wk interactions hold onto target onto active site

3) bind lowers activation energy, RXN

4) substrate into PDT

5) products leave

explain covalent modification ?

add or take away chemical groups on an enzyme, usually reversible + with hormones

What enzyme reg method controls enzyme concentration by environmental signals?

Enzyme induction

What happens in allosteric regulation?

molecules bind to a separate allosteric site that changes the enzyme’s shape and activity

What digest begins in the mouth?

Starch (salivary amylase)

Lipid (lingual lipase)

what’re the 3 phases of swallowing?

voluntary, pharngeal, esophageal

What is the main job of the stomach?

store, mix, partially chemically digest proteins, fats, control rate of food into S. intestine

What stomach glands secrete mucus to protect against HCL?

cardiac gland, pyloric gland, mucous neck cells (fundic gland)

Gastrin is made by and for?

secreted from pyloric gland, activates partietal cells to make HCL

Parietal cells make?

HCL + intrinsic factor (to use vit B12)

What is the role of chief cells?

secrete pepsinogen + gastrin lipase (lipid / protein digestion)

How are proteins digested in the stomach?

Chief cells make pepsinogen

HCL + pepsinogen = pepsin → proteins to peptides

what is absorbed in the stomach?

water, meds, alcohol, some minerals

Why do peptic ulcers form?

compromised mucus layer, so acid erodes tissue underneath

What causes GERD?

weakened lower esophageal sphincter; can eventually cause Barett’s carcinoma

Minerals, vitamins, nutrients are mainly absorbed into bloodstream in?

Small intestine

What expands the surface area in the S. intestine?

Microvilli (hair on enterocytes) < villi < folds of kerckring (circular folds)

What 2 things are produced in the pancreas?

1) digestive enzymes (amaylase, lipase, proteases)

2( bicarbonate to neutralize HCL

Where is bile made + stored?

Made - liver

Stored in gallblader

What makes up the common bile duct?

Hepatitic duct + cystic duct (carrying bile)

Pancreatic duct joins it near duodenonum with digestive enzymes + bicarbonate

The main role of the L intestine/colon is?

Water / electrolytes absorption + housing microbiome

The order of colon parts are?

Illocecal sphincter > cecum > ascending mesentery > transverse> descending > sigmoid > analcanal

What does the colon do to help move the chyme?

Segmentation (going back + forth to mix)

Peristalsis (wave to push)

Primary vs secondary constipation?

primary - physical issues: long colon, peristalsis

secondary- not enough dietary fiber, exercise, lifestyle, IBS

What’s most important when having diarrhea?

Stay hydrated as body tries to remove fluids to flush out infection

What types of bacteria live in our microbiome?

Mouth, ileum, colon: anaerobic bacteria

Proximal S. intestine: aerobic + faculative anaerobes

What does our bacteria help us with?

makes short chain fatty acids, make vitamin B + K

SFCAs make?

acetate, propionate butyrate acid

Difference in pro, pre, post biotics?

PRE= nondigestable compounds (fiber) to stimulate gut bacteria

PRO = live microbes that COULD bring benefits

POST= compounds made after microbes process the dietary compounds (ex: SCFAs_